diff --git a/crates/router/src/connector/fiserv/transformers.rs b/crates/router/src/connector/fiserv/transformers.rs
index c9c2f0c4087a..ae8eed0af314 100644
--- a/crates/router/src/connector/fiserv/transformers.rs
+++ b/crates/router/src/connector/fiserv/transformers.rs
@@ -62,6 +62,7 @@ pub struct Amount {
 pub struct TransactionDetails {
     capture_flag: Option<bool>,
     reversal_reason_code: Option<String>,
+    merchant_transaction_id: String,
 }
 
 #[derive(Default, Debug, Serialize, Eq, PartialEq)]
@@ -112,6 +113,7 @@ impl TryFrom<&types::PaymentsAuthorizeRouterData> for FiservPaymentsRequest {
                 Some(enums::CaptureMethod::Automatic) | None
             )),
             reversal_reason_code: None,
+            merchant_transaction_id: item.connector_request_reference_id.clone(),
         };
         let metadata = item.get_connector_meta()?;
         let session: SessionObject = metadata
@@ -208,6 +210,7 @@ impl TryFrom<&types::PaymentsCancelRouterData> for FiservCancelRequest {
             transaction_details: TransactionDetails {
                 capture_flag: None,
                 reversal_reason_code: Some(item.request.get_cancellation_reason()?),
+                merchant_transaction_id: item.connector_request_reference_id.clone(),
             },
         })
     }
@@ -407,6 +410,7 @@ impl TryFrom<&types::PaymentsCaptureRouterData> for FiservCaptureRequest {
             transaction_details: TransactionDetails {
                 capture_flag: Some(true),
                 reversal_reason_code: None,
+                merchant_transaction_id: item.connector_request_reference_id.clone(),
             },
             merchant_details: MerchantDetails {
                 merchant_id: auth.merchant_account,