diff --git a/.github/workflows/php-compatibility.yml b/.github/workflows/php-compatibility.yml
index 09aa667..73f6a54 100644
--- a/.github/workflows/php-compatibility.yml
+++ b/.github/workflows/php-compatibility.yml
@@ -29,5 +29,8 @@ jobs:
       - name: Install dependencies
         run: composer install
 
-      - name: Run PHP Compatibility
-        run: vendor/bin/phpcs insert-special-characters.php --standard=PHPCompatibilityWP --extensions=php --runtime-set testVersion 7.4-
\ No newline at end of file
+      - name: Run PHP Compatibility on all files.
+        run: vendor/bin/phpcs inc --standard=PHPCompatibilityWP --extensions=php --runtime-set testVersion 7.4-
+
+      - name: Run PHP Compatibility on main file.
+        run: vendor/bin/phpcs insert-special-characters.php --standard=PHPCompatibilityWP --extensions=php --runtime-set testVersion 5.6-
diff --git a/inc/plugin.php b/inc/plugin.php
new file mode 100644
index 0000000..318561f
--- /dev/null
+++ b/inc/plugin.php
@@ -0,0 +1,173 @@
+<?php
+/**
+ * Registers JS and CSS assets.
+ *
+ * @package insert-special-characters
+ */
+
+namespace InsertSpecialCharacters;
+
+/**
+ * Registers JS and CSS assets.
+ */
+function register_assets() {
+	$asset_data_file = trailingslashit( ISC_PLUGIN_PATH ) . 'build/index.asset.php';
+
+	if ( ! file_exists( $asset_data_file ) ) {
+		return;
+	}
+
+	$script_data = include $asset_data_file;
+
+	wp_register_script(
+		'insert-special-characters',
+		ISC_PLUGIN_URL . 'build/index.js',
+		$script_data['dependencies'],
+		$script_data['version'],
+		true
+	);
+
+	wp_register_style(
+		'insert-special-characters-css',
+		ISC_PLUGIN_URL . 'build/index.css',
+		array(),
+		$script_data['version']
+	);
+
+	wp_set_script_translations( 'insert-special-characters', 'insert-special-characters', ISC_PLUGIN_PATH . 'languages' );
+}
+
+add_action( 'init', __NAMESPACE__ . '\register_assets' );
+
+
+/**
+ * Enqueue the admin JavaScript assets.
+ */
+function gcm_block_enqueue_scripts() {
+
+	wp_enqueue_script( 'insert-special-characters' );
+
+	wp_enqueue_style( 'insert-special-characters-css' );
+
+	wp_add_inline_script(
+		'insert-special-characters',
+		sprintf(
+			'var tenupIscVars = window.tenupIscVars || {}; tenupIscVars = %1$s',
+			wp_json_encode(
+				array(
+					'most_read_palette' => get_most_used_palette_setting(),
+				)
+			)
+		)
+	);
+}
+add_action( 'enqueue_block_editor_assets', __NAMESPACE__ . '\gcm_block_enqueue_scripts' );
+
+/**
+ * Registers settings fields.
+ */
+function register_settings_fields() {
+	register_setting(
+		'writing',
+		'tenup_isc_most_read_palette',
+		array(
+			'type'         => 'boolean',
+			'show_in_rest' => true,
+			'default'      => false,
+		)
+	);
+
+	add_settings_section(
+		'tenup_isc_writing_section',
+		esc_html__( 'Insert Special Characters', 'insert-special-characters' ),
+		null,
+		'writing'
+	);
+
+	add_settings_field(
+		'tenup_isc_most_read_palette',
+		esc_html__( 'Most used characters palette', 'insert-special-characters' ),
+		__NAMESPACE__ . '\render_isc_writing_setting',
+		'writing',
+		'tenup_isc_writing_section',
+		array(
+			'label_for' => 'tenup_isc_most_read_palette',
+		)
+	);
+}
+add_action( 'admin_init', __NAMESPACE__ . '\register_settings_fields' );
+
+/**
+ * Renders settings fields.
+ */
+function render_isc_writing_setting() {
+	$option = get_most_used_palette_setting();
+	?>
+	<p>
+		<label for="tenup_isc_most_read_palette">
+			<input
+				type="checkbox"
+				name="tenup_isc_most_read_palette"
+				id="tenup_isc_most_read_palette"
+				<?php checked( $option, true, true ); ?>
+			>
+			<?php esc_html_e( 'Check this to enable the most used character palette.', 'insert-special-characters' ); ?>
+		</label>
+	</p>
+
+	<?php if ( $option ) : ?>
+		<p>
+			<button class="button secondary" id="isc_reset_palette" type="button" style="margin-top: 16px;">
+				<?php esc_html_e( 'Clear palette', 'insert-special-characters' ); ?>
+			</button>
+			&nbsp;
+			<?php esc_html_e( 'Press this to clear palette data.', 'insert-special-characters' ); ?>
+		</p>
+		<?php
+	endif;
+}
+
+/**
+ * Helper function to get most used character palette setting.
+ *
+ * @return boolean
+ */
+function get_most_used_palette_setting() {
+	return 'on' === get_option( 'tenup_isc_most_read_palette' );
+}
+
+/**
+ * Loads admin scripts.
+ *
+ * @param string $hook The current admin page.
+ */
+function load_admin_scripts( $hook ) {
+	if ( 'options-writing.php' !== $hook ) {
+		return;
+	}
+
+	$asset_data_file = trailingslashit( ISC_PLUGIN_PATH ) . 'build/admin.asset.php';
+
+	if ( ! file_exists( $asset_data_file ) ) {
+		return;
+	}
+
+	$script_data = include $asset_data_file;
+
+	wp_enqueue_script(
+		'insert-special-characters-admin-js',
+		ISC_PLUGIN_URL . 'build/admin.js',
+		$script_data['dependencies'],
+		$script_data['version'],
+		true
+	);
+
+	wp_localize_script(
+		'insert-special-characters-admin-js',
+		'tenupIscAdminVars',
+		array(
+			'palette_deleted_message' => __( 'Palette cleared', 'insert-special-characters' ),
+		)
+	);
+}
+add_action( 'admin_enqueue_scripts', __NAMESPACE__ . '\load_admin_scripts' );
diff --git a/insert-special-characters.php b/insert-special-characters.php
index 788a9aa..a0dd527 100644
--- a/insert-special-characters.php
+++ b/insert-special-characters.php
@@ -17,167 +17,58 @@
 
 namespace InsertSpecialCharacters;
 
-/**
- * Registers JS and CSS assets.
- */
-function register_assets() {
-	$asset_data_file = trailingslashit( plugin_dir_path( __FILE__ ) ) . 'build/index.asset.php';
-
-	if ( ! file_exists( $asset_data_file ) ) {
-		return;
-	}
-
-	$script_data = include $asset_data_file;
-
-	wp_register_script(
-		'insert-special-characters',
-		plugin_dir_url( __FILE__ ) . 'build/index.js',
-		$script_data['dependencies'],
-		$script_data['version'],
-		true
-	);
-
-	wp_register_style(
-		'insert-special-characters-css',
-		plugin_dir_url( __FILE__ ) . 'build/index.css',
-		array(),
-		$script_data['version']
-	);
-
-	wp_set_script_translations( 'insert-special-characters', 'insert-special-characters', plugin_dir_path( __FILE__ ) . 'languages' );
-}
-
-add_action( 'init', __NAMESPACE__ . '\register_assets' );
-
+define( 'ISC_PLUGIN_PATH', plugin_dir_path( __FILE__ ) );
+define( 'ISC_PLUGIN_URL', plugin_dir_url( __FILE__ ) );
 
 /**
- * Enqueue the admin JavaScript assets.
- */
-function gcm_block_enqueue_scripts() {
-
-	wp_enqueue_script( 'insert-special-characters' );
-
-	wp_enqueue_style( 'insert-special-characters-css' );
-
-	wp_add_inline_script(
-		'insert-special-characters',
-		sprintf(
-			'var tenupIscVars = window.tenupIscVars || {}; tenupIscVars = %1$s',
-			wp_json_encode(
-				array(
-					'most_read_palette' => get_most_used_palette_setting(),
-				)
-			)
-		)
-	);
-}
-add_action( 'enqueue_block_editor_assets', __NAMESPACE__ . '\gcm_block_enqueue_scripts' );
-
-/**
- * Registers settings fields.
- */
-function register_settings_fields() {
-	register_setting(
-		'writing',
-		'tenup_isc_most_read_palette',
-		array(
-			'type'         => 'boolean',
-			'show_in_rest' => true,
-			'default'      => false,
-		)
-	);
-
-	add_settings_section(
-		'tenup_isc_writing_section',
-		esc_html__( 'Insert Special Characters', 'insert-special-characters' ),
-		null,
-		'writing'
-	);
-
-	add_settings_field(
-		'tenup_isc_most_read_palette',
-		esc_html__( 'Most used characters palette', 'insert-special-characters' ),
-		__NAMESPACE__ . '\render_isc_writing_setting',
-		'writing',
-		'tenup_isc_writing_section',
-		array(
-			'label_for' => 'tenup_isc_most_read_palette',
-		)
-	);
-}
-add_action( 'admin_init', __NAMESPACE__ . '\register_settings_fields' );
-
-/**
- * Renders settings fields.
- */
-function render_isc_writing_setting() {
-	$option = get_most_used_palette_setting();
-	?>
-	<p>
-		<label for="tenup_isc_most_read_palette">
-			<input
-				type="checkbox"
-				name="tenup_isc_most_read_palette"
-				id="tenup_isc_most_read_palette"
-				<?php checked( $option, true, true ); ?>
-			>
-			<?php esc_html_e( 'Check this to enable the most used character palette.', 'insert-special-characters' ); ?>
-		</label>
-	</p>
-
-	<?php if ( $option ) : ?>
-	<p>
-		<button class="button secondary" id="isc_reset_palette" type="button" style="margin-top: 16px;">
-			<?php esc_html_e( 'Clear palette', 'insert-special-characters' ); ?>
-		</button>
-		&nbsp;
-		<?php esc_html_e( 'Press this to clear palette data.', 'insert-special-characters' ); ?>
-	</p>
-		<?php
-	endif;
-}
-
-/**
- * Helper function to get most used character palette setting.
+ * Get the minimum version of PHP required by this plugin.
+ *
+ * @since 1.0.8
  *
- * @return boolean
+ * @return string Minimum version required.
  */
-function get_most_used_palette_setting() {
-	return 'on' === get_option( 'tenup_isc_most_read_palette' );
+function minimum_php_requirement() {
+	return '7.4';
 }
 
 /**
- * Loads admin scripts.
+ * Whether PHP installation meets the minimum requirements
+ *
+ * @since 1.0.8
  *
- * @param string $hook The current admin page.
+ * @return bool True if meets minimum requirements, false otherwise.
  */
-function load_admin_scripts( $hook ) {
-	if ( 'options-writing.php' !== $hook ) {
-		return;
-	}
-
-	$asset_data_file = trailingslashit( plugin_dir_path( __FILE__ ) ) . 'build/admin.asset.php';
-
-	if ( ! file_exists( $asset_data_file ) ) {
-		return;
-	}
-
-	$script_data = include $asset_data_file;
+function site_meets_php_requirements() {
+	return version_compare( phpversion(), minimum_php_requirement(), '>=' );
+}
 
-	wp_enqueue_script(
-		'insert-special-characters-admin-js',
-		plugin_dir_url( __FILE__ ) . 'build/admin.js',
-		$script_data['dependencies'],
-		$script_data['version'],
-		true
+// Try to load the plugin files, ensuring our PHP version is met first.
+if ( ! site_meets_php_requirements() ) {
+	add_action(
+		'admin_notices',
+		function() {
+			?>
+			<div class="notice notice-error">
+				<p>
+					<?php
+					echo wp_kses_post(
+						sprintf(
+							/* translators: %s: Minimum required PHP version */
+							__( 'Insert Special Characters requires PHP version %s or later. Please upgrade PHP or disable the plugin.', 'insert-special-characters' ),
+							esc_html( minimum_php_requirement() )
+						)
+					);
+					?>
+				</p>
+			</div>
+			<?php
+		}
 	);
+	return;
+}
 
-	wp_localize_script(
-		'insert-special-characters-admin-js',
-		'tenupIscAdminVars',
-		array(
-			'palette_deleted_message' => __( 'Palette cleared', 'insert-special-characters' ),
-		)
-	);
+if ( ! site_meets_php_requirements() ) {
+	return;
 }
-add_action( 'admin_enqueue_scripts', __NAMESPACE__ . '\load_admin_scripts' );
+
+require_once __DIR__ . '/inc/plugin.php';
diff --git a/package-lock.json b/package-lock.json
index b91ed29..3d9bd6d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13176,9 +13176,16 @@
       "license": "ISC"
     },
     "node_modules/nanoid": {
-      "version": "3.3.4",
+      "version": "3.3.6",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.6.tgz",
+      "integrity": "sha512-BGcqMMJuToF7i1rt+2PWSNVnWIkGCU78jBG3RxO/bZlnZPK2Cmi2QaffxGO/2RvWi9sL+FAiRiXMgsyxQ1DIDA==",
       "dev": true,
-      "license": "MIT",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/ai"
+        }
+      ],
       "bin": {
         "nanoid": "bin/nanoid.cjs"
       },
@@ -14145,7 +14152,9 @@
       }
     },
     "node_modules/postcss": {
-      "version": "8.4.20",
+      "version": "8.4.31",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
+      "integrity": "sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==",
       "dev": true,
       "funding": [
         {
@@ -14155,11 +14164,14 @@
         {
           "type": "tidelift",
           "url": "https://tidelift.com/funding/github/npm/postcss"
+        },
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/ai"
         }
       ],
-      "license": "MIT",
       "dependencies": {
-        "nanoid": "^3.3.4",
+        "nanoid": "^3.3.6",
         "picocolors": "^1.0.0",
         "source-map-js": "^1.0.2"
       },
@@ -27436,7 +27448,9 @@
       "dev": true
     },
     "nanoid": {
-      "version": "3.3.4",
+      "version": "3.3.6",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.6.tgz",
+      "integrity": "sha512-BGcqMMJuToF7i1rt+2PWSNVnWIkGCU78jBG3RxO/bZlnZPK2Cmi2QaffxGO/2RvWi9sL+FAiRiXMgsyxQ1DIDA==",
       "dev": true
     },
     "natural-compare": {
@@ -28052,10 +28066,12 @@
       }
     },
     "postcss": {
-      "version": "8.4.20",
+      "version": "8.4.31",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
+      "integrity": "sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==",
       "dev": true,
       "requires": {
-        "nanoid": "^3.3.4",
+        "nanoid": "^3.3.6",
         "picocolors": "^1.0.0",
         "source-map-js": "^1.0.2"
       }