diff --git a/changelog/refactor-tokenized-ece-base-implementation b/changelog/refactor-tokenized-ece-base-implementation
new file mode 100644
index 00000000000..d642531bbcf
--- /dev/null
+++ b/changelog/refactor-tokenized-ece-base-implementation
@@ -0,0 +1,5 @@
+Significance: patch
+Type: update
+Comment: feat: tokenized cart ECE base implementation
+
+
diff --git a/client/express-checkout/index.js b/client/express-checkout/index.js
index 8b35c61db89..f43720bb9d3 100644
--- a/client/express-checkout/index.js
+++ b/client/express-checkout/index.js
@@ -12,7 +12,8 @@ import {
 	getExpressCheckoutButtonStyleSettings,
 	getExpressCheckoutData,
 	normalizeLineItems,
-} from './utils/index';
+	displayLoginConfirmation,
+} from './utils';
 import {
 	onAbortPaymentHandler,
 	onCancelHandler,
@@ -23,7 +24,6 @@ import {
 	shippingAddressChangeHandler,
 	shippingRateChangeHandler,
 } from './event-handlers';
-import { displayLoginConfirmation } from './utils';
 
 jQuery( ( $ ) => {
 	// Don't load if blocks checkout is being loaded.
diff --git a/client/express-checkout/utils/index.ts b/client/express-checkout/utils/index.ts
index f6089857abc..7b56b702045 100644
--- a/client/express-checkout/utils/index.ts
+++ b/client/express-checkout/utils/index.ts
@@ -68,6 +68,9 @@ export interface WCPayExpressCheckoutParams {
 		platform_tracker: string;
 		shipping: string;
 		update_shipping: string;
+		tokenized_cart_nonce: string;
+		tokenized_cart_session_nonce: string;
+		store_api_nonce: string;
 	};
 
 	/**
diff --git a/client/tokenized-express-checkout/__tests__/cart-api.test.js b/client/tokenized-express-checkout/__tests__/cart-api.test.js
new file mode 100644
index 00000000000..b60bffd6299
--- /dev/null
+++ b/client/tokenized-express-checkout/__tests__/cart-api.test.js
@@ -0,0 +1,196 @@
+/**
+ * External dependencies
+ */
+import apiFetch from '@wordpress/api-fetch';
+
+/**
+ * Internal dependencies
+ */
+import ExpressCheckoutCartApi from '../cart-api';
+
+jest.mock( '@wordpress/api-fetch', () => jest.fn() );
+
+global.wcpayExpressCheckoutParams = {};
+global.wcpayExpressCheckoutParams.nonce = {};
+global.wcpayExpressCheckoutParams.nonce.store_api_nonce =
+	'global_store_api_nonce';
+global.wcpayExpressCheckoutParams.nonce.tokenized_cart_nonce =
+	'global_tokenized_cart_nonce';
+global.wcpayExpressCheckoutParams.nonce.tokenized_cart_session_nonce =
+	'global_tokenized_cart_session_nonce';
+global.wcpayExpressCheckoutParams.checkout = {};
+global.wcpayExpressCheckoutParams.checkout.currency_code = 'USD';
+
+describe( 'ExpressCheckoutCartApi', () => {
+	afterEach( () => {
+		jest.resetAllMocks();
+	} );
+
+	it( 'should allow to create an anonymous cart for a specific class instance, without affecting other instances', async () => {
+		global.wcpayExpressCheckoutParams.button_context = 'product';
+		const headers = new Headers();
+		headers.append(
+			'X-WooPayments-Tokenized-Cart-Session',
+			'tokenized_cart_session'
+		);
+		headers.append( 'Nonce', 'nonce-value' );
+		apiFetch.mockResolvedValue( {
+			headers: headers,
+			json: () => Promise.resolve( {} ),
+		} );
+
+		const api = new ExpressCheckoutCartApi();
+		const anotherApi = new ExpressCheckoutCartApi();
+
+		api.useSeparateCart();
+		await api.getCart();
+
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'GET',
+				path: expect.stringContaining( '/wc/store/v1/cart' ),
+				headers: expect.objectContaining( {
+					'X-WooPayments-Tokenized-Cart-Session': '',
+					'X-WooPayments-Tokenized-Cart-Session-Nonce':
+						'global_tokenized_cart_session_nonce',
+					'X-WooPayments-Tokenized-Cart-Nonce':
+						'global_tokenized_cart_nonce',
+					Nonce: 'global_store_api_nonce',
+				} ),
+			} )
+		);
+
+		apiFetch.mockClear();
+		apiFetch.mockResolvedValue( {
+			headers: new Headers(),
+			json: () => Promise.resolve( {} ),
+		} );
+
+		await api.updateCustomer( {
+			billing_address: { first_name: 'First' },
+		} );
+		expect( apiFetch ).toHaveBeenLastCalledWith(
+			expect.objectContaining( {
+				method: 'POST',
+				path: expect.stringContaining(
+					'/wc/store/v1/cart/update-customer'
+				),
+				headers: expect.objectContaining( {
+					'X-WooPayments-Tokenized-Cart': true,
+					'X-WooPayments-Tokenized-Cart-Session-Nonce':
+						'global_tokenized_cart_session_nonce',
+					'X-WooPayments-Tokenized-Cart-Nonce':
+						'global_tokenized_cart_nonce',
+					'X-WooPayments-Tokenized-Cart-Session':
+						'tokenized_cart_session',
+					Nonce: 'nonce-value',
+				} ),
+				data: expect.objectContaining( {
+					billing_address: { first_name: 'First' },
+				} ),
+			} )
+		);
+
+		apiFetch.mockClear();
+		apiFetch.mockResolvedValue( {
+			headers: new Headers(),
+			json: () => Promise.resolve( {} ),
+		} );
+		await anotherApi.updateCustomer( {
+			billing_address: { last_name: 'Last' },
+		} );
+		expect( apiFetch ).toHaveBeenLastCalledWith(
+			expect.objectContaining( {
+				method: 'POST',
+				path: expect.stringContaining(
+					'/wc/store/v1/cart/update-customer'
+				),
+				// in this case, no additional headers should have been submitted.
+				headers: expect.objectContaining( {
+					'X-WooPayments-Tokenized-Cart': true,
+					'X-WooPayments-Tokenized-Cart-Nonce':
+						'global_tokenized_cart_nonce',
+					Nonce: 'global_store_api_nonce',
+				} ),
+				data: expect.objectContaining( {
+					billing_address: { last_name: 'Last' },
+				} ),
+			} )
+		);
+	} );
+
+	it( 'should call `/cart/update-customer` with the global headers if the cart is not anonymous', async () => {
+		global.wcpayExpressCheckoutParams.button_context = 'cart';
+		apiFetch.mockResolvedValue( {
+			headers: new Headers(),
+			json: () => Promise.resolve( {} ),
+		} );
+		const api = new ExpressCheckoutCartApi();
+
+		await api.updateCustomer( {
+			billing_address: { last_name: 'Last' },
+		} );
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'POST',
+				path: expect.stringContaining(
+					'/wc/store/v1/cart/update-customer'
+				),
+				// in this case, no additional headers should have been submitted.
+				headers: expect.objectContaining( {
+					'X-WooPayments-Tokenized-Cart': true,
+					'X-WooPayments-Tokenized-Cart-Nonce':
+						'global_tokenized_cart_nonce',
+				} ),
+				data: expect.objectContaining( {
+					billing_address: { last_name: 'Last' },
+				} ),
+			} )
+		);
+	} );
+
+	it( 'should store received header information for subsequent usage', async () => {
+		global.wcpayExpressCheckoutParams.button_context = 'cart';
+		const headers = new Headers();
+		headers.append( 'Nonce', 'nonce-value' );
+		apiFetch.mockResolvedValue( {
+			headers,
+			json: () => Promise.resolve( {} ),
+		} );
+		const api = new ExpressCheckoutCartApi();
+
+		await api.getCart();
+
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'GET',
+				path: expect.stringContaining( '/wc/store/v1/cart' ),
+				headers: expect.objectContaining( {
+					'X-WooPayments-Tokenized-Cart-Session-Nonce': undefined,
+					'X-WooPayments-Tokenized-Cart-Nonce':
+						'global_tokenized_cart_nonce',
+				} ),
+			} )
+		);
+
+		await api.updateCustomer( {
+			billing_address: { last_name: 'Last' },
+		} );
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'POST',
+				path: expect.stringContaining(
+					'/wc/store/v1/cart/update-customer'
+				),
+				// in this case, no additional headers should have been submitted.
+				headers: expect.objectContaining( {
+					'X-WooPayments-Tokenized-Cart-Session-Nonce': undefined,
+					'X-WooPayments-Tokenized-Cart': true,
+					'X-WooPayments-Tokenized-Cart-Nonce':
+						'global_tokenized_cart_nonce',
+					Nonce: 'nonce-value',
+				} ),
+			} )
+		);
+	} );
+} );
diff --git a/client/tokenized-express-checkout/__tests__/order-api.js b/client/tokenized-express-checkout/__tests__/order-api.js
new file mode 100644
index 00000000000..8f95a0887b8
--- /dev/null
+++ b/client/tokenized-express-checkout/__tests__/order-api.js
@@ -0,0 +1,128 @@
+/**
+ * External dependencies
+ */
+import apiFetch from '@wordpress/api-fetch';
+
+/**
+ * Internal dependencies
+ */
+import ExpressCheckoutOrderApi from '../order-api';
+
+jest.mock( '@wordpress/api-fetch', () => jest.fn() );
+
+global.wcpayExpressCheckoutParams = {};
+global.wcpayExpressCheckoutParams.nonce = {};
+global.wcpayExpressCheckoutParams.nonce.store_api_nonce =
+	'global_store_api_nonce';
+
+describe( 'ExpressCheckoutOrderApi', () => {
+	afterEach( () => {
+		jest.resetAllMocks();
+	} );
+
+	it( 'gets order data with the provided arguments', async () => {
+		const api = new ExpressCheckoutOrderApi( {
+			orderId: '1',
+			key: 'key_123',
+			billingEmail: 'cheese@toast.com',
+		} );
+
+		await api.getCart();
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'GET',
+				path: expect.stringMatching(
+					// I am using a regex to ensure the order of the parameters doesn't matter.
+					/(?=.*\/wc\/store\/v1\/order\/1)(?=.*billing_email=cheese%40toast.com)(?=.*key=key_123)/
+				),
+			} )
+		);
+	} );
+
+	it( 'places an order', async () => {
+		const api = new ExpressCheckoutOrderApi( {
+			orderId: '1',
+			key: 'key_123',
+			billingEmail: 'cheese@toast.com',
+		} );
+
+		await api.placeOrder( {
+			billing_address: {
+				first_name: 'Fake',
+			},
+			shipping_address: {
+				first_name: 'Test',
+			},
+			anythingElse: 'passedThrough',
+		} );
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'POST',
+				path: '/wc/store/v1/checkout/1',
+				headers: expect.objectContaining( {
+					Nonce: 'global_store_api_nonce',
+				} ),
+				data: expect.objectContaining( {
+					key: 'key_123',
+					billing_email: 'cheese@toast.com',
+					billing_address: undefined,
+					shipping_address: undefined,
+					anythingElse: 'passedThrough',
+				} ),
+			} )
+		);
+	} );
+
+	it( 'places an order with the previous API request data', async () => {
+		const api = new ExpressCheckoutOrderApi( {
+			orderId: '1',
+			key: 'key_123',
+			billingEmail: 'cheese@toast.com',
+		} );
+
+		apiFetch.mockResolvedValueOnce( {
+			billing_address: {
+				first_name: 'Fake',
+				last_name: 'Test',
+			},
+			shipping_address: {
+				first_name: 'Test',
+				last_name: 'Fake',
+			},
+		} );
+		await api.getCart();
+
+		await api.placeOrder( {
+			billing_address: {
+				first_name: 'Fake',
+			},
+			shipping_address: {
+				first_name: 'Test',
+			},
+			anythingElse: 'passedThrough',
+		} );
+
+		expect( apiFetch ).toHaveBeenCalledWith(
+			expect.objectContaining( {
+				method: 'POST',
+				path: '/wc/store/v1/checkout/1',
+				headers: expect.objectContaining( {
+					Nonce: 'global_store_api_nonce',
+				} ),
+				data: expect.objectContaining( {
+					key: 'key_123',
+					billing_email: 'cheese@toast.com',
+					billing_address: expect.objectContaining( {
+						first_name: 'Fake',
+						last_name: 'Test',
+					} ),
+					shipping_address: expect.objectContaining( {
+						first_name: 'Test',
+						last_name: 'Fake',
+					} ),
+					anythingElse: 'passedThrough',
+				} ),
+			} )
+		);
+	} );
+} );
diff --git a/client/tokenized-express-checkout/utils/checkPaymentMethodIsAvailable.js b/client/tokenized-express-checkout/blocks/checkPaymentMethodIsAvailable.js
similarity index 100%
rename from client/tokenized-express-checkout/utils/checkPaymentMethodIsAvailable.js
rename to client/tokenized-express-checkout/blocks/checkPaymentMethodIsAvailable.js
diff --git a/client/tokenized-express-checkout/blocks/index.js b/client/tokenized-express-checkout/blocks/index.js
index d2cefd85eb7..ef5f747a074 100644
--- a/client/tokenized-express-checkout/blocks/index.js
+++ b/client/tokenized-express-checkout/blocks/index.js
@@ -9,7 +9,7 @@ import { __ } from '@wordpress/i18n';
 import { PAYMENT_METHOD_NAME_EXPRESS_CHECKOUT_ELEMENT } from 'wcpay/checkout/constants';
 import { getConfig } from 'wcpay/utils/checkout';
 import ExpressCheckoutContainer from './components/express-checkout-container';
-import { checkPaymentMethodIsAvailable } from '../utils/checkPaymentMethodIsAvailable';
+import { checkPaymentMethodIsAvailable } from './checkPaymentMethodIsAvailable';
 
 export const tokenizedExpressCheckoutElementApplePay = ( api ) => ( {
 	paymentMethodId: PAYMENT_METHOD_NAME_EXPRESS_CHECKOUT_ELEMENT,
diff --git a/client/tokenized-payment-request/cart-api.js b/client/tokenized-express-checkout/cart-api.js
similarity index 94%
rename from client/tokenized-payment-request/cart-api.js
rename to client/tokenized-express-checkout/cart-api.js
index 52fcc25b46d..277cce18c09 100644
--- a/client/tokenized-payment-request/cart-api.js
+++ b/client/tokenized-express-checkout/cart-api.js
@@ -10,9 +10,9 @@ import { addQueryArgs } from '@wordpress/url';
 /**
  * Internal dependencies
  */
-import { getPaymentRequestData } from './frontend-utils';
+import { getExpressCheckoutData } from './utils';
 
-export default class PaymentRequestCartApi {
+export default class ExpressCheckoutCartApi {
 	// Used on product pages to interact with an anonymous cart.
 	// This anonymous cart is separate from the customer's cart, which might contain additional products.
 	// This functionality is also useful to calculate product/shipping pricing (and shipping needs)
@@ -32,21 +32,21 @@ export default class PaymentRequestCartApi {
 			path: addQueryArgs( options.path, {
 				// `wcpayPaymentRequestParams` will always be defined if this file is needed.
 				// If there's an issue with it, ask yourself why this file is queued and `wcpayPaymentRequestParams` isn't present.
-				currency: getPaymentRequestData(
+				currency: getExpressCheckoutData(
 					'checkout'
 				).currency_code.toUpperCase(),
 			} ),
 			headers: {
 				// the Store API nonce, which could later be overwritten in subsequent requests.
-				Nonce: getPaymentRequestData( 'nonce' ).store_api_nonce,
+				Nonce: getExpressCheckoutData( 'nonce' ).store_api_nonce,
 				// needed for validation of address data, etc.
 				'X-WooPayments-Tokenized-Cart-Nonce':
-					getPaymentRequestData( 'nonce' ).tokenized_cart_nonce ||
+					getExpressCheckoutData( 'nonce' ).tokenized_cart_nonce ||
 					undefined,
 				// necessary to validate any request made to the backend from the PDP.
 				'X-WooPayments-Tokenized-Cart-Session-Nonce':
-					getPaymentRequestData( 'button_context' ) === 'product'
-						? getPaymentRequestData( 'nonce' )
+					getExpressCheckoutData( 'button_context' ) === 'product'
+						? getExpressCheckoutData( 'nonce' )
 								.tokenized_cart_session_nonce
 						: undefined,
 				...this.cartRequestHeaders,
@@ -170,7 +170,7 @@ export default class PaymentRequestCartApi {
 			method: 'POST',
 			path: '/wc/store/v1/cart/add-item',
 			data: applyFilters(
-				'wcpay.payment-request.cart-add-item',
+				'wcpay.express-checkout.cart-add-item',
 				productData
 			),
 		} );
diff --git a/client/tokenized-express-checkout/index.js b/client/tokenized-express-checkout/index.js
index 8b35c61db89..3b2fcb57df2 100644
--- a/client/tokenized-express-checkout/index.js
+++ b/client/tokenized-express-checkout/index.js
@@ -12,7 +12,8 @@ import {
 	getExpressCheckoutButtonStyleSettings,
 	getExpressCheckoutData,
 	normalizeLineItems,
-} from './utils/index';
+	displayLoginConfirmation,
+} from './utils';
 import {
 	onAbortPaymentHandler,
 	onCancelHandler,
@@ -23,7 +24,9 @@ import {
 	shippingAddressChangeHandler,
 	shippingRateChangeHandler,
 } from './event-handlers';
-import { displayLoginConfirmation } from './utils';
+import ExpressCheckoutCartApi from './cart-api';
+import ExpressCheckoutOrderApi from './order-api';
+import { getUPEConfig } from 'wcpay/utils/checkout';
 
 jQuery( ( $ ) => {
 	// Don't load if blocks checkout is being loaded.
@@ -56,6 +59,15 @@ jQuery( ( $ ) => {
 		}
 	);
 
+	let cartApi = new ExpressCheckoutCartApi();
+	if ( getExpressCheckoutData( 'button_context' ) === 'pay_for_order' ) {
+		cartApi = new ExpressCheckoutOrderApi( {
+			orderId: getUPEConfig( 'order_id' ),
+			key: getUPEConfig( 'key' ),
+			billingEmail: getUPEConfig( 'billing_email' ),
+		} );
+	}
+
 	let wcPayECEError = '';
 	const defaultErrorMessage = __(
 		'There was an error getting the product information.',
diff --git a/client/tokenized-payment-request/order-api.js b/client/tokenized-express-checkout/order-api.js
similarity index 91%
rename from client/tokenized-payment-request/order-api.js
rename to client/tokenized-express-checkout/order-api.js
index 13c580e752c..96b1896cc59 100644
--- a/client/tokenized-payment-request/order-api.js
+++ b/client/tokenized-express-checkout/order-api.js
@@ -3,9 +3,13 @@
  */
 import apiFetch from '@wordpress/api-fetch';
 import { addQueryArgs } from '@wordpress/url';
-import { getPaymentRequestData } from './frontend-utils';
 
-export default class PaymentRequestOrderApi {
+/**
+ * Internal dependencies
+ */
+import { getExpressCheckoutData } from './utils';
+
+export default class ExpressCheckoutOrderApi {
 	// parameters used in every request, just in different ways.
 	orderId;
 	key;
@@ -44,7 +48,7 @@ export default class PaymentRequestOrderApi {
 			method: 'POST',
 			path: `/wc/store/v1/checkout/${ this.orderId }`,
 			headers: {
-				Nonce: getPaymentRequestData( 'nonce' ).store_api_nonce,
+				Nonce: getExpressCheckoutData( 'nonce' ).store_api_nonce,
 			},
 			data: {
 				...paymentData,
diff --git a/client/tokenized-express-checkout/test/event-handlers.js b/client/tokenized-express-checkout/test/event-handlers.js
deleted file mode 100644
index 8c3d8a1c28b..00000000000
--- a/client/tokenized-express-checkout/test/event-handlers.js
+++ /dev/null
@@ -1,571 +0,0 @@
-/**
- * Internal dependencies
- */
-import {
-	shippingAddressChangeHandler,
-	shippingRateChangeHandler,
-	onConfirmHandler,
-} from '../event-handlers';
-import {
-	normalizeLineItems,
-	normalizeShippingAddress,
-	normalizeOrderData,
-	normalizePayForOrderData,
-} from '../utils';
-
-describe( 'Express checkout event handlers', () => {
-	describe( 'shippingAddressChangeHandler', () => {
-		let api;
-		let event;
-		let elements;
-
-		beforeEach( () => {
-			api = {
-				expressCheckoutECECalculateShippingOptions: jest.fn(),
-			};
-			event = {
-				address: {
-					recipient: 'John Doe',
-					addressLine: [ '123 Main St' ],
-					city: 'New York',
-					state: 'NY',
-					country: 'US',
-					postal_code: '10001',
-				},
-				resolve: jest.fn(),
-				reject: jest.fn(),
-			};
-			elements = {
-				update: jest.fn(),
-			};
-		} );
-
-		afterEach( () => {
-			jest.clearAllMocks();
-		} );
-
-		test( 'should handle successful response', async () => {
-			const response = {
-				result: 'success',
-				total: { amount: 1000 },
-				shipping_options: [
-					{ id: 'option_1', label: 'Standard Shipping' },
-				],
-				displayItems: [ { label: 'Sample Item', amount: 500 } ],
-			};
-
-			api.expressCheckoutECECalculateShippingOptions.mockResolvedValue(
-				response
-			);
-
-			await shippingAddressChangeHandler( api, event, elements );
-
-			const expectedNormalizedAddress = normalizeShippingAddress(
-				event.address
-			);
-			expect(
-				api.expressCheckoutECECalculateShippingOptions
-			).toHaveBeenCalledWith( expectedNormalizedAddress );
-
-			const expectedNormalizedLineItems = normalizeLineItems(
-				response.displayItems
-			);
-			expect( elements.update ).toHaveBeenCalledWith( { amount: 1000 } );
-			expect( event.resolve ).toHaveBeenCalledWith( {
-				shippingRates: response.shipping_options,
-				lineItems: expectedNormalizedLineItems,
-			} );
-			expect( event.reject ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should handle unsuccessful response', async () => {
-			const response = {
-				result: 'error',
-			};
-
-			api.expressCheckoutECECalculateShippingOptions.mockResolvedValue(
-				response
-			);
-
-			await shippingAddressChangeHandler( api, event, elements );
-
-			const expectedNormalizedAddress = normalizeShippingAddress(
-				event.address
-			);
-			expect(
-				api.expressCheckoutECECalculateShippingOptions
-			).toHaveBeenCalledWith( expectedNormalizedAddress );
-			expect( elements.update ).not.toHaveBeenCalled();
-			expect( event.resolve ).not.toHaveBeenCalled();
-			expect( event.reject ).toHaveBeenCalled();
-		} );
-
-		test( 'should handle API call failure', async () => {
-			api.expressCheckoutECECalculateShippingOptions.mockRejectedValue(
-				new Error( 'API error' )
-			);
-
-			await shippingAddressChangeHandler( api, event, elements );
-
-			const expectedNormalizedAddress = normalizeShippingAddress(
-				event.address
-			);
-			expect(
-				api.expressCheckoutECECalculateShippingOptions
-			).toHaveBeenCalledWith( expectedNormalizedAddress );
-			expect( elements.update ).not.toHaveBeenCalled();
-			expect( event.resolve ).not.toHaveBeenCalled();
-			expect( event.reject ).toHaveBeenCalled();
-		} );
-	} );
-
-	describe( 'shippingRateChangeHandler', () => {
-		let api;
-		let event;
-		let elements;
-
-		beforeEach( () => {
-			api = {
-				expressCheckoutECEUpdateShippingDetails: jest.fn(),
-			};
-			event = {
-				shippingRate: {
-					id: 'rate_1',
-					label: 'Standard Shipping',
-					amount: 500,
-				},
-				resolve: jest.fn(),
-				reject: jest.fn(),
-			};
-			elements = {
-				update: jest.fn(),
-			};
-		} );
-
-		afterEach( () => {
-			jest.clearAllMocks();
-		} );
-
-		test( 'should handle successful response', async () => {
-			const response = {
-				result: 'success',
-				total: { amount: 1500 },
-				displayItems: [ { label: 'Sample Item', amount: 1000 } ],
-			};
-
-			api.expressCheckoutECEUpdateShippingDetails.mockResolvedValue(
-				response
-			);
-
-			await shippingRateChangeHandler( api, event, elements );
-
-			const expectedNormalizedLineItems = normalizeLineItems(
-				response.displayItems
-			);
-			expect(
-				api.expressCheckoutECEUpdateShippingDetails
-			).toHaveBeenCalledWith( event.shippingRate );
-			expect( elements.update ).toHaveBeenCalledWith( { amount: 1500 } );
-			expect( event.resolve ).toHaveBeenCalledWith( {
-				lineItems: expectedNormalizedLineItems,
-			} );
-			expect( event.reject ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should handle unsuccessful response', async () => {
-			const response = {
-				result: 'error',
-			};
-
-			api.expressCheckoutECEUpdateShippingDetails.mockResolvedValue(
-				response
-			);
-
-			await shippingRateChangeHandler( api, event, elements );
-
-			expect(
-				api.expressCheckoutECEUpdateShippingDetails
-			).toHaveBeenCalledWith( event.shippingRate );
-			expect( elements.update ).not.toHaveBeenCalled();
-			expect( event.resolve ).not.toHaveBeenCalled();
-			expect( event.reject ).toHaveBeenCalled();
-		} );
-
-		test( 'should handle API call failure', async () => {
-			api.expressCheckoutECEUpdateShippingDetails.mockRejectedValue(
-				new Error( 'API error' )
-			);
-
-			await shippingRateChangeHandler( api, event, elements );
-
-			expect(
-				api.expressCheckoutECEUpdateShippingDetails
-			).toHaveBeenCalledWith( event.shippingRate );
-			expect( elements.update ).not.toHaveBeenCalled();
-			expect( event.resolve ).not.toHaveBeenCalled();
-			expect( event.reject ).toHaveBeenCalled();
-		} );
-	} );
-
-	describe( 'onConfirmHandler', () => {
-		let api;
-		let stripe;
-		let elements;
-		let completePayment;
-		let abortPayment;
-		let event;
-		let order;
-
-		beforeEach( () => {
-			api = {
-				expressCheckoutECECreateOrder: jest.fn(),
-				expressCheckoutECEPayForOrder: jest.fn(),
-				confirmIntent: jest.fn(),
-			};
-			stripe = {
-				createPaymentMethod: jest.fn(),
-			};
-			elements = {
-				submit: jest.fn(),
-			};
-			completePayment = jest.fn();
-			abortPayment = jest.fn();
-			event = {
-				billingDetails: {
-					name: 'John Doe',
-					email: 'john.doe@example.com',
-					address: {
-						organization: 'Some Company',
-						country: 'US',
-						line1: '123 Main St',
-						line2: 'Apt 4B',
-						city: 'New York',
-						state: 'NY',
-						postal_code: '10001',
-					},
-					phone: '(123) 456-7890',
-				},
-				shippingAddress: {
-					name: 'John Doe',
-					organization: 'Some Company',
-					address: {
-						country: 'US',
-						line1: '123 Main St',
-						line2: 'Apt 4B',
-						city: 'New York',
-						state: 'NY',
-						postal_code: '10001',
-					},
-				},
-				shippingRate: { id: 'rate_1' },
-				expressPaymentType: 'express',
-			};
-			order = 123;
-			global.window.wcpayFraudPreventionToken = 'token123';
-		} );
-
-		afterEach( () => {
-			jest.clearAllMocks();
-		} );
-
-		test( 'should abort payment if elements.submit fails', async () => {
-			elements.submit.mockResolvedValue( {
-				error: { message: 'Submit error' },
-			} );
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event
-			);
-
-			expect( elements.submit ).toHaveBeenCalled();
-			expect( abortPayment ).toHaveBeenCalledWith(
-				event,
-				'Submit error'
-			);
-			expect( completePayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should abort payment if stripe.createPaymentMethod fails', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				error: { message: 'Payment method error' },
-			} );
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event
-			);
-
-			expect( elements.submit ).toHaveBeenCalled();
-			expect( stripe.createPaymentMethod ).toHaveBeenCalledWith( {
-				elements,
-			} );
-			expect( abortPayment ).toHaveBeenCalledWith(
-				event,
-				'Payment method error'
-			);
-			expect( completePayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should abort payment if expressCheckoutECECreateOrder fails', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECECreateOrder.mockResolvedValue( {
-				result: 'error',
-				messages: 'Order creation error',
-			} );
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event
-			);
-
-			const expectedOrderData = normalizeOrderData( event, 'pm_123' );
-			expect( api.expressCheckoutECECreateOrder ).toHaveBeenCalledWith(
-				expectedOrderData
-			);
-			expect( abortPayment ).toHaveBeenCalledWith(
-				event,
-				'Order creation error'
-			);
-			expect( completePayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should complete payment if confirmationRequest is true', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECECreateOrder.mockResolvedValue( {
-				result: 'success',
-				redirect: 'https://example.com/redirect',
-			} );
-			api.confirmIntent.mockReturnValue( true );
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event
-			);
-
-			expect( api.confirmIntent ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( completePayment ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( abortPayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should complete payment if confirmationRequest returns a redirect URL', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECECreateOrder.mockResolvedValue( {
-				result: 'success',
-				redirect: 'https://example.com/redirect',
-			} );
-			api.confirmIntent.mockResolvedValue(
-				'https://example.com/confirmation_redirect'
-			);
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event
-			);
-
-			expect( api.confirmIntent ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( completePayment ).toHaveBeenCalledWith(
-				'https://example.com/confirmation_redirect'
-			);
-			expect( abortPayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should abort payment if confirmIntent throws an error', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECECreateOrder.mockResolvedValue( {
-				result: 'success',
-				redirect: 'https://example.com/redirect',
-			} );
-			api.confirmIntent.mockRejectedValue(
-				new Error( 'Intent confirmation error' )
-			);
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event
-			);
-
-			expect( api.confirmIntent ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( abortPayment ).toHaveBeenCalledWith(
-				event,
-				'Intent confirmation error'
-			);
-			expect( completePayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should abort payment if expressCheckoutECEPayForOrder fails', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECEPayForOrder.mockResolvedValue( {
-				result: 'error',
-				messages: 'Order creation error',
-			} );
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event,
-				order
-			);
-
-			const expectedOrderData = normalizePayForOrderData(
-				event,
-				'pm_123'
-			);
-			expect( api.expressCheckoutECEPayForOrder ).toHaveBeenCalledWith(
-				123,
-				expectedOrderData
-			);
-			expect( abortPayment ).toHaveBeenCalledWith(
-				event,
-				'Order creation error'
-			);
-			expect( completePayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should complete payment (pay for order) if confirmationRequest is true', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECEPayForOrder.mockResolvedValue( {
-				result: 'success',
-				redirect: 'https://example.com/redirect',
-			} );
-			api.confirmIntent.mockReturnValue( true );
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event,
-				order
-			);
-
-			expect( api.confirmIntent ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( completePayment ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( abortPayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should complete payment (pay for order) if confirmationRequest returns a redirect URL', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECEPayForOrder.mockResolvedValue( {
-				result: 'success',
-				redirect: 'https://example.com/redirect',
-			} );
-			api.confirmIntent.mockResolvedValue(
-				'https://example.com/confirmation_redirect'
-			);
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event,
-				order
-			);
-
-			expect( api.confirmIntent ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( completePayment ).toHaveBeenCalledWith(
-				'https://example.com/confirmation_redirect'
-			);
-			expect( abortPayment ).not.toHaveBeenCalled();
-		} );
-
-		test( 'should abort payment (pay for order) if confirmIntent throws an error', async () => {
-			elements.submit.mockResolvedValue( {} );
-			stripe.createPaymentMethod.mockResolvedValue( {
-				paymentMethod: { id: 'pm_123' },
-			} );
-			api.expressCheckoutECEPayForOrder.mockResolvedValue( {
-				result: 'success',
-				redirect: 'https://example.com/redirect',
-			} );
-			api.confirmIntent.mockRejectedValue(
-				new Error( 'Intent confirmation error' )
-			);
-
-			await onConfirmHandler(
-				api,
-				stripe,
-				elements,
-				completePayment,
-				abortPayment,
-				event,
-				order
-			);
-
-			expect( api.confirmIntent ).toHaveBeenCalledWith(
-				'https://example.com/redirect'
-			);
-			expect( abortPayment ).toHaveBeenCalledWith(
-				event,
-				'Intent confirmation error'
-			);
-			expect( completePayment ).not.toHaveBeenCalled();
-		} );
-	} );
-} );
diff --git a/client/tokenized-express-checkout/utils/test/index.ts b/client/tokenized-express-checkout/utils/__tests__/index.test.js
similarity index 84%
rename from client/tokenized-express-checkout/utils/test/index.ts
rename to client/tokenized-express-checkout/utils/__tests__/index.test.js
index e1e61edf988..651bef1d0dd 100644
--- a/client/tokenized-express-checkout/utils/test/index.ts
+++ b/client/tokenized-express-checkout/utils/__tests__/index.test.js
@@ -1,18 +1,14 @@
 /**
  * Internal dependencies
  */
-import {
-	WCPayExpressCheckoutParams,
-	getErrorMessageFromNotice,
-	getExpressCheckoutData,
-} from '../index';
+import { getErrorMessageFromNotice, getExpressCheckoutData } from '..';
 
 describe( 'Express checkout utils', () => {
 	test( 'getExpressCheckoutData returns null for missing option', () => {
 		expect(
 			getExpressCheckoutData(
 				// Force wrong usage, just in case this is called from JS with incorrect params.
-				'does-not-exist' as keyof WCPayExpressCheckoutParams
+				'does-not-exist'
 			)
 		).toBeNull();
 	} );
@@ -22,7 +18,7 @@ describe( 'Express checkout utils', () => {
 		// the type assertion is fine.
 		window.wcpayExpressCheckoutParams = {
 			ajax_url: 'test',
-		} as WCPayExpressCheckoutParams;
+		};
 
 		expect( getExpressCheckoutData( 'ajax_url' ) ).toBe( 'test' );
 	} );
diff --git a/client/tokenized-express-checkout/utils/test/normalize.js b/client/tokenized-express-checkout/utils/__tests__/normalize.test.js
similarity index 100%
rename from client/tokenized-express-checkout/utils/test/normalize.js
rename to client/tokenized-express-checkout/utils/__tests__/normalize.test.js
diff --git a/client/tokenized-express-checkout/utils/index.ts b/client/tokenized-express-checkout/utils/index.ts
index f6089857abc..9b92ec023ba 100644
--- a/client/tokenized-express-checkout/utils/index.ts
+++ b/client/tokenized-express-checkout/utils/index.ts
@@ -1,109 +1,10 @@
 /**
  * Internal dependencies
  */
+import { WCPayExpressCheckoutParams } from 'wcpay/express-checkout/utils';
 export * from './normalize';
 import { getDefaultBorderRadius } from 'wcpay/utils/express-checkout';
 
-interface MyWindow extends Window {
-	wcpayExpressCheckoutParams: WCPayExpressCheckoutParams;
-}
-
-declare let window: MyWindow;
-
-/**
- * An /incomplete/ representation of the data that is loaded into the frontend for the Express Checkout.
- */
-export interface WCPayExpressCheckoutParams {
-	ajax_url: string;
-
-	/**
-	 * Express Checkout Button style configuration.
-	 */
-	button: {
-		type: string;
-		theme: string;
-		height: string;
-		locale: string;
-		branded_type: string;
-		radius: number;
-	};
-
-	/**
-	 * Indicates in which context the button is being displayed.
-	 */
-	button_context: 'checkout' | 'cart' | 'product' | 'pay_for_order';
-	checkout: {
-		country_code: string;
-		currency_code: string;
-		needs_payer_phone: boolean;
-		needs_shipping: boolean;
-	};
-
-	/**
-	 * Indicaters whether the page has a Cart or Checkout Block on it.
-	 */
-	has_block: boolean;
-
-	/**
-	 * True if we're on the checkout page.
-	 */
-	is_checkout_page: boolean;
-
-	/**
-	 * True if we're on a product page.
-	 */
-	is_product_page: boolean;
-
-	/**
-	 * True if we're on the pay for order page.
-	 */
-	is_pay_for_order_page: boolean;
-	nonce: {
-		add_to_cart: string;
-		checkout: string;
-		empty_cart: string;
-		get_cart_details: string;
-		get_selected_product_data: string;
-		pay_for_order: string;
-		platform_tracker: string;
-		shipping: string;
-		update_shipping: string;
-	};
-
-	/**
-	 * Product specific options.
-	 */
-	product: {
-		needs_shipping: boolean;
-		currency: string;
-		shippingOptions: {
-			id: string;
-			label: string;
-			detail: string;
-			amount: number;
-		};
-	};
-
-	/**
-	 * Settings for the user authentication dialog and redirection.
-	 */
-	login_confirmation: { message: string; redirect_url: string } | false;
-
-	stripe: {
-		accountId: string;
-		locale: string;
-		publishableKey: string;
-	};
-	total_label: string;
-	wc_ajax_url: string;
-}
-
-declare global {
-	interface Window {
-		wcpayExpressCheckoutParams?: WCPayExpressCheckoutParams;
-	}
-}
-
 export const getExpressCheckoutData = <
 	K extends keyof WCPayExpressCheckoutParams
 >(
@@ -111,7 +12,9 @@ export const getExpressCheckoutData = <
 ) => {
 	if ( typeof window.wcpayExpressCheckoutParams !== 'undefined' ) {
 		return window.wcpayExpressCheckoutParams[ key ] ?? null;
-	} else if ( typeof window.wc?.wcSettings !== 'undefined' ) {
+	}
+
+	if ( typeof window.wc?.wcSettings !== 'undefined' ) {
 		return window.wc.wcSettings.getSetting( 'ece_data' )?.[ key ] ?? null;
 	}
 
diff --git a/includes/express-checkout/class-wc-payments-express-checkout-ajax-handler.php b/includes/express-checkout/class-wc-payments-express-checkout-ajax-handler.php
index 87c820f23f4..03c4feb32db 100644
--- a/includes/express-checkout/class-wc-payments-express-checkout-ajax-handler.php
+++ b/includes/express-checkout/class-wc-payments-express-checkout-ajax-handler.php
@@ -9,6 +9,7 @@
 	exit;
 }
 
+use WCPay\Constants\Country_Code;
 use WCPay\Exceptions\Invalid_Price_Exception;
 use WCPay\Logger;
 
@@ -44,6 +45,19 @@ public function init() {
 		add_action( 'wc_ajax_wcpay_ece_get_cart_details', [ $this, 'ajax_get_cart_details' ] );
 		add_action( 'wc_ajax_wcpay_ece_update_shipping_method', [ $this, 'ajax_update_shipping_method' ] );
 		add_action( 'wc_ajax_wcpay_ece_get_selected_product_data', [ $this, 'ajax_get_selected_product_data' ] );
+
+		if ( WC_Payments_Features::is_tokenized_cart_ece_enabled() ) {
+			add_action(
+				'woocommerce_store_api_checkout_update_order_from_request',
+				[
+					$this,
+					'tokenized_cart_set_payment_method_type',
+				],
+				10,
+				2
+			);
+			add_filter( 'rest_pre_dispatch', [ $this, 'tokenized_cart_store_api_address_normalization' ], 10, 3 );
+		}
 	}
 
 	/**
@@ -421,4 +435,138 @@ public function ajax_add_to_cart() {
 
 		wp_send_json( $data );
 	}
+
+	/**
+	 * Updates the checkout order based on the request, to set the Apple Pay/Google Pay payment method title.
+	 *
+	 * @param \WC_Order        $order The order to be updated.
+	 * @param \WP_REST_Request $request Store API request to update the order.
+	 */
+	public function tokenized_cart_set_payment_method_type( \WC_Order $order, \WP_REST_Request $request ) {
+		if ( ! isset( $request['payment_method'] ) || 'woocommerce_payments' !== $request['payment_method'] ) {
+			return;
+		}
+
+		if ( empty( $request['payment_data'] ) ) {
+			return;
+		}
+
+		$payment_data = [];
+		foreach ( $request['payment_data'] as $data ) {
+			$payment_data[ sanitize_key( $data['key'] ) ] = wc_clean( $data['value'] );
+		}
+
+		if ( empty( $payment_data['payment_request_type'] ) ) {
+			return;
+		}
+
+		$payment_request_type = wc_clean( wp_unslash( $payment_data['payment_request_type'] ) );
+
+		$payment_method_titles = [
+			'apple_pay'  => 'Apple Pay',
+			'google_pay' => 'Google Pay',
+		];
+
+		$suffix = apply_filters( 'wcpay_payment_request_payment_method_title_suffix', 'WooPayments' );
+		if ( ! empty( $suffix ) ) {
+			$suffix = " ($suffix)";
+		}
+
+		$payment_method_title = isset( $payment_method_titles[ $payment_request_type ] ) ? $payment_method_titles[ $payment_request_type ] : 'Payment Request';
+		$order->set_payment_method_title( $payment_method_title . $suffix );
+	}
+
+	/**
+	 * Google Pay/Apple Pay parameters for address data might need some massaging for some of the countries.
+	 * Ensuring that the Store API doesn't throw a `rest_invalid_param` error message for some of those scenarios.
+	 *
+	 * @param mixed            $response Response to replace the requested version with.
+	 * @param \WP_REST_Server  $server Server instance.
+	 * @param \WP_REST_Request $request Request used to generate the response.
+	 *
+	 * @return mixed
+	 */
+	public function tokenized_cart_store_api_address_normalization( $response, $server, $request ) {
+		if ( 'true' !== $request->get_header( 'X-WooPayments-Tokenized-Cart' ) ) {
+			return $response;
+		}
+
+		// header added as additional layer of security.
+		$nonce = $request->get_header( 'X-WooPayments-Tokenized-Cart-Nonce' );
+		if ( ! wp_verify_nonce( $nonce, 'woopayments_tokenized_cart_nonce' ) ) {
+			return $response;
+		}
+
+		// This route is used to get shipping rates.
+		// GooglePay/ApplePay might provide us with "trimmed" zip codes.
+		// If that's the case, let's temporarily allow to skip the zip code validation, in order to get some shipping rates.
+		$is_update_customer_route = $request->get_route() === '/wc/store/v1/cart/update-customer';
+		if ( $is_update_customer_route ) {
+			add_filter( 'woocommerce_validate_postcode', [ $this, 'maybe_skip_postcode_validation' ], 10, 3 );
+		}
+
+		$request_data = $request->get_json_params();
+		if ( isset( $request_data['shipping_address'] ) ) {
+			$request->set_param( 'shipping_address', $this->transform_ece_address_state_data( $request_data['shipping_address'] ) );
+			// on the "update customer" route, GooglePay/Apple pay might provide redacted postcode data.
+			// we need to modify the zip code to ensure that shipping zone identification still works.
+			if ( $is_update_customer_route ) {
+				$request->set_param( 'shipping_address', $this->transform_ece_address_postcode_data( $request_data['shipping_address'] ) );
+			}
+		}
+		if ( isset( $request_data['billing_address'] ) ) {
+			$request->set_param( 'billing_address', $this->transform_ece_address_state_data( $request_data['billing_address'] ) );
+			// on the "update customer" route, GooglePay/Apple pay might provide redacted postcode data.
+			// we need to modify the zip code to ensure that shipping zone identification still works.
+			if ( $is_update_customer_route ) {
+				$request->set_param( 'billing_address', $this->transform_ece_address_postcode_data( $request_data['billing_address'] ) );
+			}
+		}
+
+		return $response;
+	}
+
+	/**
+	 * Transform a GooglePay/ApplePay state address data fields into values that are valid for WooCommerce.
+	 *
+	 * @param array $address The address to normalize from the GooglePay/ApplePay request.
+	 *
+	 * @return array
+	 */
+	private function transform_ece_address_state_data( $address ) {
+		$country = $address['country'] ?? '';
+		if ( empty( $country ) ) {
+			return $address;
+		}
+
+		// States from Apple Pay or Google Pay are in long format, we need their short format..
+		$state = $address['state'] ?? '';
+		if ( ! empty( $state ) ) {
+			$address['state'] = $this->express_checkout_button_helper->get_normalized_state( $state, $country );
+		}
+
+		return $address;
+	}
+
+	/**
+	 * Transform a GooglePay/ApplePay postcode address data fields into values that are valid for WooCommerce.
+	 *
+	 * @param array $address The address to normalize from the GooglePay/ApplePay request.
+	 *
+	 * @return array
+	 */
+	private function transform_ece_address_postcode_data( $address ) {
+		$country = $address['country'] ?? '';
+		if ( empty( $country ) ) {
+			return $address;
+		}
+
+		// Normalizes postal code in case of redacted data from Apple Pay or Google Pay.
+		$postcode = $address['postcode'] ?? '';
+		if ( ! empty( $postcode ) ) {
+			$address['postcode'] = $this->express_checkout_button_helper->get_normalized_postal_code( $postcode, $country );
+		}
+
+		return $address;
+	}
 }
diff --git a/includes/express-checkout/class-wc-payments-express-checkout-button-handler.php b/includes/express-checkout/class-wc-payments-express-checkout-button-handler.php
index 6a0113d2048..3e18af89016 100644
--- a/includes/express-checkout/class-wc-payments-express-checkout-button-handler.php
+++ b/includes/express-checkout/class-wc-payments-express-checkout-button-handler.php
@@ -231,15 +231,19 @@ public function scripts() {
 				'locale'         => WC_Payments_Utils::convert_to_stripe_locale( get_locale() ),
 			],
 			'nonce'              => [
-				'get_cart_details'          => wp_create_nonce( 'wcpay-get-cart-details' ),
-				'shipping'                  => wp_create_nonce( 'wcpay-payment-request-shipping' ),
-				'update_shipping'           => wp_create_nonce( 'wcpay-update-shipping-method' ),
-				'checkout'                  => wp_create_nonce( 'woocommerce-process_checkout' ),
-				'add_to_cart'               => wp_create_nonce( 'wcpay-add-to-cart' ),
-				'empty_cart'                => wp_create_nonce( 'wcpay-empty-cart' ),
-				'get_selected_product_data' => wp_create_nonce( 'wcpay-get-selected-product-data' ),
-				'platform_tracker'          => wp_create_nonce( 'platform_tracks_nonce' ),
-				'pay_for_order'             => wp_create_nonce( 'pay_for_order' ),
+				'get_cart_details'             => wp_create_nonce( 'wcpay-get-cart-details' ),
+				'shipping'                     => wp_create_nonce( 'wcpay-payment-request-shipping' ),
+				'update_shipping'              => wp_create_nonce( 'wcpay-update-shipping-method' ),
+				'checkout'                     => wp_create_nonce( 'woocommerce-process_checkout' ),
+				'add_to_cart'                  => wp_create_nonce( 'wcpay-add-to-cart' ),
+				'empty_cart'                   => wp_create_nonce( 'wcpay-empty-cart' ),
+				'get_selected_product_data'    => wp_create_nonce( 'wcpay-get-selected-product-data' ),
+				'platform_tracker'             => wp_create_nonce( 'platform_tracks_nonce' ),
+				'pay_for_order'                => wp_create_nonce( 'pay_for_order' ),
+				// needed to communicate via the Store API.
+				'tokenized_cart_nonce'         => wp_create_nonce( 'woopayments_tokenized_cart_nonce' ),
+				'tokenized_cart_session_nonce' => wp_create_nonce( 'woopayments_tokenized_cart_session_nonce' ),
+				'store_api_nonce'              => wp_create_nonce( 'wc_store_api' ),
 			],
 			'checkout'           => [
 				'currency_code'              => strtolower( get_woocommerce_currency() ),