diff --git a/changelog/update-license-field-improvements b/changelog/update-license-field-improvements
new file mode 100644
index 0000000000..7936ee7a88
--- /dev/null
+++ b/changelog/update-license-field-improvements
@@ -0,0 +1,4 @@
+Significance: minor
+Type: fix
+
+Warn users when they attempt to enter a Unified license key into the standalone license key field
diff --git a/src/Common/Integrations/Harbor/PUE.php b/src/Common/Integrations/Harbor/PUE.php
index 02132afb28..6fad004124 100644
--- a/src/Common/Integrations/Harbor/PUE.php
+++ b/src/Common/Integrations/Harbor/PUE.php
@@ -41,6 +41,9 @@ protected function do_register(): void {
 		add_filter( 'stellarwp/uplink/tec/license_get_key', [ $this, 'filter_stellarwp_uplink_tec_license_get_key' ], 10, 2 );
 		add_filter( 'tec_common_uplink_auth_url', [ $this, 'filter_stellarwp_uplink_tec_authorize_button_url' ], 10, 2 );
 		add_filter( 'pue_get_update_url', [ $this, 'filter_pue_get_update_url' ], 10, 2 );
+		add_filter( 'tec_common_pue_pre_validate_key', [ $this, 'filter_tec_common_pue_pre_validate_key' ], 10, 3 );
+		add_filter( 'tribe_settings_save_field_value', [ $this, 'prevent_storing_unified_license_key' ], 10, 2 );
+		add_filter( 'tribe_license_fields', [ $this, 'readonly_and_disable_harbor_managed_license_fields' ], 30 );
 	}
 
 	/**
@@ -56,6 +59,154 @@ public function unregister(): void {
 		remove_filter( 'stellarwp/uplink/tec/license_get_key', [ $this, 'filter_stellarwp_uplink_tec_license_get_key' ] );
 		remove_filter( 'tec_common_uplink_auth_url', [ $this, 'filter_stellarwp_uplink_tec_authorize_button_url' ] );
 		remove_filter( 'pue_get_update_url', [ $this, 'filter_pue_get_update_url' ] );
+		remove_filter( 'tec_common_pue_pre_validate_key', [ $this, 'filter_tec_common_pue_pre_validate_key' ] );
+		remove_filter( 'tribe_settings_save_field_value', [ $this, 'prevent_storing_unified_license_key' ] );
+		remove_filter( 'tribe_license_fields', [ $this, 'readonly_and_disable_harbor_managed_license_fields' ], 30 );
+	}
+
+	/**
+	 * Modify the Harbor-managed legacy fields and make them
+	 * readonly and disabled when the product is licensed via Harbor.
+	 *
+	 * @since TBD
+	 *
+	 * @param array $fields The license fields.
+	 *
+	 * @return array
+	 */
+	public function readonly_and_disable_harbor_managed_license_fields( array $fields ): array {
+		foreach ( $fields as $field_id => &$field ) {
+			if ( ! is_array( $field ) || ! is_string( $field_id ) ) {
+				continue;
+			}
+
+			if ( ! str_starts_with( $field_id, 'pue_install_key_' ) ) {
+				continue;
+			}
+
+			if ( ( $field['type'] ?? '' ) !== 'license_key' ) {
+				continue;
+			}
+
+			$product = str_replace( [ 'pue_install_key_', '_' ], [ '', '-' ], $field_id );
+			if ( ! $this->harbor->is_license_field_managed_by_harbor( $product ) ) {
+				continue;
+			}
+
+			$field['attributes'] = array_merge(
+				$field['attributes'] ?? [],
+				[
+					'disabled' => 'disabled',
+					'readonly' => 'readonly',
+				]
+			);
+		}
+
+		return $fields;
+	}
+
+	/**
+	 * Short-circuit legacy PUE key validation for Harbor unified licenses.
+	 *
+	 * Harbor-managed products already use the unified key, so remote validation is
+	 * skipped. Unified keys pasted into non-managed product fields are rejected with
+	 * a link to the LW License Manager.
+	 *
+	 * @since TBD
+	 *
+	 * @param array|null                $response Early response, or null to continue.
+	 * @param string                    $key      The license key being validated.
+	 * @param \Tribe__PUE__Checker|null $checker  The PUE checker instance.
+	 *
+	 * @return array|null
+	 */
+	public function filter_tec_common_pue_pre_validate_key( ?array $response, string $key, $checker ): ?array {
+		if ( null !== $response ) {
+			return $response;
+		}
+
+		if ( ! $checker instanceof \Tribe__PUE__Checker ) {
+			return $response;
+		}
+
+		$slug = $checker->get_slug();
+
+		if ( $this->harbor->is_license_field_managed_by_harbor( $slug ) ) {
+			return [
+				'status'  => 1,
+				'message' => sprintf(
+					/* translators: URL to the Liquid Web License Manager */
+					__( 'Licensed via <a href="%s" target="_blank">Unified License Manager</a>', 'tribe-common' ),
+					esc_url( lw_harbor_get_license_page_url() ),
+				),
+			];
+		}
+
+		if ( $this->harbor->is_unified_license_key( $key ) ) {
+			return [
+				'status'  => 0,
+				'message' => $this->harbor->get_unified_license_key_entry_error_message(),
+			];
+		}
+
+		return $response;
+	}
+
+	/**
+	 * Prevent storing unified license keys in per-product PUE options.
+	 *
+	 * Harbor-managed fields ignore submitted values so the unified key is not written
+	 * into product options. Unified keys pasted into non-managed fields are rejected
+	 * and the previously stored product key is kept.
+	 *
+	 * @since TBD
+	 *
+	 * @param mixed  $value    The field value about to be saved.
+	 * @param string $field_id The settings field ID.
+	 *
+	 * @return mixed
+	 */
+	public function prevent_storing_unified_license_key( $value, $field_id ) {
+		if ( ! is_string( $field_id ) || ! str_starts_with( $field_id, 'pue_install_key_' ) ) {
+			return $value;
+		}
+
+		$product = str_replace( [ 'pue_install_key_', '_' ], [ '', '-' ], $field_id );
+
+		if ( $this->harbor->is_license_field_managed_by_harbor( $product ) ) {
+			return $this->get_stored_product_license_key( $field_id );
+		}
+
+		if ( is_string( $value ) && $this->harbor->is_unified_license_key( $value ) ) {
+			return $this->get_stored_product_license_key( $field_id );
+		}
+
+		return $value;
+	}
+
+	/**
+	 * Get the stored product license key without Harbor option overlays.
+	 *
+	 * @since TBD
+	 *
+	 * @param string $option_name The option name.
+	 *
+	 * @return string
+	 */
+	private function get_stored_product_license_key( string $option_name ): string {
+		$had_filter = has_filter( 'pre_option', [ $this, 'filter_pre_get_option' ] );
+
+		if ( $had_filter ) {
+			remove_filter( 'pre_option', [ $this, 'filter_pre_get_option' ], 10 );
+		}
+
+		$stored = (string) get_option( $option_name, '' );
+
+		if ( $had_filter ) {
+			add_filter( 'pre_option', [ $this, 'filter_pre_get_option' ], 10, 3 );
+		}
+
+		return $stored;
 	}
 
 	/**
@@ -86,7 +237,7 @@ public function filter_pue_get_update_url( string $update_url, string $slug ): s
 	 *
 	 * @return ?string
 	 */
-	public function filter_stellarwp_uplink_tec_license_get_key( ?string $license, Uplink_Resource $uplink_resource ) {
+	public function filter_stellarwp_uplink_tec_license_get_key( ?string $license, Uplink_Resource $uplink_resource ): ?string {
 		$harbor_slug = $this->harbor->get_harbor_product_slug( $uplink_resource->get_slug() );
 		if ( ! $this->harbor->is_product_licensed( $harbor_slug ) ) {
 			return $license;
@@ -122,13 +273,25 @@ public function filter_pre_get_option( $value, $option, $default_value ) {
 	}
 
 	/**
-	 * Filter the pre HTTP request.
+	 * Short-circuit PUE license validation HTTP requests for Harbor-licensed products.
+	 *
+	 * Legacy PUE code (e.g. Tribe__PUE__Checker) validates license keys by POSTing to
+	 * `/api/plugins/v2/license/validate` on Stellar's licensing servers. For unified licensed
+	 * sites, the license is managed by Harbor and at the whole site level, so those remote
+	 * calls are unnecessary and may fail or return stale data.
+	 *
+	 * This filter intercepts those license validation requests via `pre_http_request` and returns
+	 * a synthetic HTTP 200 response shaped like the PUE API, built from Harbor's cached
+	 * license and catalog data.
+	 *
+	 * Only requests to the validate endpoint for products reported as licensed by Harbor
+	 * are intercepted. All other HTTP traffic is left unchanged.
 	 *
 	 * @since 6.11.0
 	 *
-	 * @param false|array|WP_Error $response    The response.
-	 * @param array                $parsed_args The parsed arguments.
-	 * @param string               $url         The URL.
+	 * @param false|array|\WP_Error $response    The response.
+	 * @param array                 $parsed_args The parsed arguments.
+	 * @param string                $url         The URL.
 	 *
 	 * @return false|array
 	 */
diff --git a/src/Common/Libraries/Harbor.php b/src/Common/Libraries/Harbor.php
index e55f6efbc5..1bc227007e 100644
--- a/src/Common/Libraries/Harbor.php
+++ b/src/Common/Libraries/Harbor.php
@@ -29,12 +29,21 @@
  * @package TEC\Common\Libraries\Harbor
  */
 class Harbor extends Controller_Contract {
+	/**
+	 * Prefix for Liquid Web unified license keys.
+	 *
+	 * @since TBD
+	 *
+	 * @var string
+	 */
+	private const UNIFIED_LICENSE_KEY_PREFIX = 'LWSW-';
+
 	/**
 	 * The TEC product slug to Harbor product slug map.
 	 *
 	 * @since 6.11.0
 	 *
-	 * @var array
+	 * @var array<string, string>
 	 */
 	private const TEC_PRODUCT_SLUG_TO_HARBOR_PRODUCT_SLUG_MAP = [
 		'the-events-calendar'    => 'the-events-calendar',
@@ -81,6 +90,9 @@ public function do_register(): void {
 
 		add_filter( 'lw-harbor/legacy_licenses', [ $this,'register_legacy_licenses' ] );
 		add_filter( 'lw_harbor/premium_plugin_exists', [ $this, 'register_premium_plugin_exists' ] );
+		// Runs even when Harbor does not fully load (no premium plugin), so unified keys
+		// pasted into free-plugin PUE fields still get a clear guidance message.
+		add_filter( 'tec_common_pue_pre_validate_key', [ $this, 'filter_tec_common_pue_pre_validate_key' ], 10, 3 );
 
 		Harbor_Provider::init();
 
@@ -105,6 +117,7 @@ public function do_register(): void {
 	public function unregister(): void {
 		remove_filter( 'lw-harbor/legacy_licenses', [ $this,'register_legacy_licenses' ] );
 		remove_filter( 'lw_harbor/premium_plugin_exists', [ $this, 'register_premium_plugin_exists' ] );
+		remove_filter( 'tec_common_pue_pre_validate_key', [ $this, 'filter_tec_common_pue_pre_validate_key' ] );
 		remove_action( 'init', [ $this, 'decorate_uplinks_auth_url' ] );
 	}
 
@@ -119,6 +132,48 @@ public function decorate_uplinks_auth_url(): void {
 		$this->container->bind( Auth_Url::class, Auth_URL_Decorator::class );
 	}
 
+	/**
+	 * Reject unified license keys when Harbor is not loaded.
+	 *
+	 * Without a premium plugin, Harbor never fires `lw_harbor/loaded` and the PUE
+	 * Harbor integration is not registered — so this callback is the only guard that
+	 * stops a unified key from being sent through legacy PUE validation.
+	 *
+	 * @since TBD
+	 *
+	 * @param array|null                $response Early response, or null to continue.
+	 * @param string                    $key      The license key being validated.
+	 * @param \Tribe__PUE__Checker|null $checker  The PUE checker instance.
+	 *
+	 * @return array|null
+	 */
+	public function filter_tec_common_pue_pre_validate_key( ?array $response, string $key, $checker ): ?array {
+		if ( null !== $response ) {
+			return $response;
+		}
+
+		// Bail out if harbor is loaded.
+		if ( did_action( 'lw_harbor/loaded' ) ) {
+			return $response;
+		}
+
+		if ( ! $this->is_unified_license_key( $key ) ) {
+			return $response;
+		}
+
+		return [
+			'status'  => 0,
+			'message' => sprintf(
+				/* translators: %s: My account page link. */
+				__(
+					'This is a unified license key. To activate it, install The Events Calendar Pro or Event Tickets Pro, then add your license in the Unified License Manager. You can download the plugin from <a href="%s" target="_blank">your account</a>.',
+					'tribe-common'
+				),
+				esc_url( $this->get_portal_url() )
+			),
+		];
+	}
+
 	/**
 	 * Get the premium plugin existence callbacks.
 	 *
@@ -232,7 +287,7 @@ public function register_legacy_licenses( array $licenses ): array {
 		return array_values(
 			array_filter(
 				$licenses,
-				static fn( array $license ): bool => ! empty( $license['key'] ) && ! str_starts_with( $license['key'], 'LWSW-' )
+				fn( array $license ): bool => ! empty( $license['key'] ) && ! $this->is_unified_license_key( $license['key'] )
 			)
 		);
 	}
@@ -265,6 +320,62 @@ public function is_product_licensed( string $product ): bool {
 		return lw_harbor_is_feature_available( $product );
 	}
 
+	/**
+	 * Whether a license key uses the unified Liquid Web format.
+	 *
+	 * @since TBD
+	 *
+	 * @param string $key The license key.
+	 *
+	 * @return bool
+	 */
+	public function is_unified_license_key( string $key ): bool {
+		return str_starts_with( trim( $key ), self::UNIFIED_LICENSE_KEY_PREFIX );
+	}
+
+	/**
+	 * Whether a TEC product license field is managed by Harbor.
+	 *
+	 * When true, the unified license key should be shown read-only and should not
+	 * be validated through legacy PUE per-product fields.
+	 *
+	 * Checks that the product's license is actually active/valid for this site, not
+	 * merely that the customer's tier entitles them to it — a customer can be entitled
+	 * to a product without having activated it here, in which case a legacy per-product
+	 * key should still be accepted.
+	 *
+	 * @since TBD
+	 *
+	 * @param string $tec_product_slug The TEC product slug.
+	 *
+	 * @return bool
+	 */
+	public function is_license_field_managed_by_harbor( string $tec_product_slug ): bool {
+		if ( ! lw_harbor_has_unified_license_key() ) {
+			return false;
+		}
+
+		return lw_harbor_is_feature_enabled(
+			$this->get_harbor_product_slug( $tec_product_slug )
+		);
+	}
+
+	/**
+	 * Error message shown when a unified license key is entered in a per-product field.
+	 *
+	 * @since TBD
+	 *
+	 * @return string
+	 */
+	public function get_unified_license_key_entry_error_message(): string {
+		return sprintf(
+			/* translators: %1$s: opening anchor tag, %2$s: closing anchor tag. */
+			__( 'This is a unified license key. Please %1$sclick here%2$s to enter it in the Unified License Manager.', 'tribe-common' ),
+			'<a href="' . esc_url( lw_harbor_get_license_page_url() ) . '" target=_blank>',
+			'</a>'
+		);
+	}
+
 	/**
 	 * Get the unified license key if the feature is enabled.
 	 *
diff --git a/src/Tribe/PUE/Checker.php b/src/Tribe/PUE/Checker.php
index 9184cbccb4..528e22aa81 100755
--- a/src/Tribe/PUE/Checker.php
+++ b/src/Tribe/PUE/Checker.php
@@ -1238,6 +1238,23 @@ public function validate_key( string $key, bool $network = false ): array {
 				return [];
 			}
 
+			/**
+			 * Filter early license key validation before remote PUE checks.
+			 *
+			 * Returning a non-null array short-circuits remote validation and is used as
+			 * the AJAX/validation response. Return null to continue normal validation.
+			 *
+			 * @since TBD
+			 *
+			 * @param array|null          $response Early response, or null to continue.
+			 * @param string              $key      The license key being validated.
+			 * @param Tribe__PUE__Checker $checker  The PUE checker instance.
+			 */
+			$pre_validate = apply_filters( 'tec_common_pue_pre_validate_key', null, $key, $this );
+			if ( is_array( $pre_validate ) ) {
+				return $pre_validate;
+			}
+
 			$uplink_resource = $this->get_uplink_resource( $this->get_slug() );
 
 			if ( $uplink_resource ) {
diff --git a/tests/integration/Tribe/Common/Integrations/Harbor/PUE_Test.php b/tests/integration/Tribe/Common/Integrations/Harbor/PUE_Test.php
index 1a1d9c200c..a127a7ec08 100644
--- a/tests/integration/Tribe/Common/Integrations/Harbor/PUE_Test.php
+++ b/tests/integration/Tribe/Common/Integrations/Harbor/PUE_Test.php
@@ -6,6 +6,7 @@
 use TEC\Common\Libraries\Harbor;
 use TEC\Common\StellarWP\Uplink\Resources\Plugin as Uplink_Plugin;
 use Tribe\Tests\Traits\With_Harbor_State;
+use Tribe\Tests\Traits\With_Uopz;
 
 /**
  * Exercises the four PUE filter hooks that the Harbor consolidation introduces
@@ -20,6 +21,7 @@
  */
 class PUE_Test extends WPTestCase {
 	use With_Harbor_State;
+	use With_Uopz;
 
 	/**
 	 * The priority airplane-mode (a wp-browser test harness plugin) registers its
@@ -351,4 +353,179 @@ public function auth_url_decorator_provider(): array {
 			'non-matching slug leaves URL untouched'        => [ 'events-calendar-pro', 'https://example.com/seating-connect/', false ],
 		];
 	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_skip_remote_validation_for_harbor_managed_product(): void {
+		$remote_call_count = 0;
+		// validate_key() → request_info() uses wp_remote_post for remote PUE checks.
+		$this->set_fn_return(
+			'wp_remote_post',
+			static function () use ( &$remote_call_count ) {
+				++$remote_call_count;
+
+				return new \WP_Error( 'unexpected_remote_validation', 'Remote validation should not be performed.' );
+			},
+			true
+		);
+
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$checker  = new \Tribe__PUE__Checker( 'deprecated', 'events-calendar-pro', [], 'events-calendar-pro/events-calendar-pro.php' );
+		$response = $checker->validate_key( 'any-key-value' );
+
+		$this->assertSame( 0, $remote_call_count, 'Remote validation should not be performed for Harbor-managed products.' );
+		$this->assertSame( 1, $response['status'] );
+		$this->assertStringContainsString( 'Unified License Manager', $response['message'] );
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_reject_unified_key_for_non_harbor_managed_product(): void {
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$checker  = new \Tribe__PUE__Checker( 'deprecated', 'tribe-filterbar', [], 'the-events-calendar-filterbar/the-events-calendar-filterbar.php' );
+		$response = $checker->validate_key( 'LWSW-PASTED-INTO-WRONG-FIELD' );
+
+		$this->assertSame( 0, $response['status'] );
+		$this->assertStringContainsString( 'unified license key', strtolower( wp_strip_all_tags( $response['message'] ) ) );
+		$this->assertStringContainsString( '<a href="', $response['message'] );
+	}
+
+	/**
+	 * @test
+	 * @dataProvider pre_validate_key_provider
+	 */
+	public function it_should_handle_pre_validate_key_filter(
+		string $slug,
+		string $plugin_file,
+		string $key,
+		?int $expected_status,
+		?string $expected_message_fragment
+	): void {
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$checker = new \Tribe__PUE__Checker( 'deprecated', $slug, [], $plugin_file );
+		$result  = apply_filters( 'tec_common_pue_pre_validate_key', null, $key, $checker );
+
+		if ( null === $expected_status ) {
+			$this->assertNull( $result );
+
+			return;
+		}
+
+		$this->assertIsArray( $result );
+		$this->assertSame( $expected_status, $result['status'] );
+		$this->assertStringContainsString(
+			$expected_message_fragment,
+			strtolower( wp_strip_all_tags( $result['message'] ) )
+		);
+	}
+
+	public function pre_validate_key_provider(): array {
+		return [
+			'legacy key on non-managed product passes through' => [
+				'tribe-filterbar',
+				'the-events-calendar-filterbar/the-events-calendar-filterbar.php',
+				'legacy-product-key',
+				null,
+				null,
+			],
+			'harbor-managed product short-circuits as valid'   => [
+				'events-calendar-pro',
+				'events-calendar-pro/events-calendar-pro.php',
+				'any-key-value',
+				1,
+				'unified license manager',
+			],
+			'unified key on non-managed product is rejected'  => [
+				'tribe-filterbar',
+				'the-events-calendar-filterbar/the-events-calendar-filterbar.php',
+				'LWSW-PASTED-INTO-WRONG-FIELD',
+				0,
+				'unified license key',
+			],
+		];
+	}
+
+	/**
+	 * @test
+	 * @dataProvider save_license_field_value_provider
+	 */
+	public function it_should_handle_license_field_value_on_save(
+		string $field_id,
+		string $submitted_value,
+		?string $stored_value,
+		string $expected_saved
+	): void {
+		if ( null !== $stored_value ) {
+			update_option( $field_id, $stored_value );
+		}
+
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$saved = apply_filters( 'tribe_settings_save_field_value', $submitted_value, $field_id );
+
+		$this->assertSame( $expected_saved, $saved );
+
+		if ( null !== $stored_value ) {
+			delete_option( $field_id );
+		}
+	}
+
+	public function save_license_field_value_provider(): array {
+		return [
+			'harbor-managed field ignores submitted value'       => [
+				'pue_install_key_events_calendar_pro',
+				'LWSW-SHOULD-NOT-BE-STORED',
+				'legacy-ecp-key',
+				'legacy-ecp-key',
+			],
+			'unified key on non-managed field keeps stored value' => [
+				'pue_install_key_tribe_filterbar',
+				'LWSW-PASTED-INTO-WRONG-FIELD',
+				'legacy-filterbar-key',
+				'legacy-filterbar-key',
+			],
+			'normal key on non-managed field is stored'            => [
+				'pue_install_key_tribe_filterbar',
+				'new-legacy-filterbar-key',
+				null,
+				'new-legacy-filterbar-key',
+			],
+		];
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_disable_harbor_managed_legacy_license_fields(): void {
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$fields = apply_filters(
+			'tribe_license_fields',
+			[
+				'pue_install_key_events_calendar_pro' => [
+					'type'       => 'license_key',
+					'attributes' => [],
+				],
+				'pue_install_key_tribe_filterbar'     => [
+					'type'       => 'license_key',
+					'attributes' => [],
+				],
+			]
+		);
+
+		$this->assertSame( 'disabled', $fields['pue_install_key_events_calendar_pro']['attributes']['disabled'] );
+		$this->assertSame( 'readonly', $fields['pue_install_key_events_calendar_pro']['attributes']['readonly'] );
+
+		$this->assertArrayNotHasKey( 'disabled', $fields['pue_install_key_tribe_filterbar']['attributes'] );
+	}
 }
diff --git a/tests/integration/Tribe/Common/Libraries/Harbor_Test.php b/tests/integration/Tribe/Common/Libraries/Harbor_Test.php
index 12e4af8a79..1cb1f34766 100644
--- a/tests/integration/Tribe/Common/Libraries/Harbor_Test.php
+++ b/tests/integration/Tribe/Common/Libraries/Harbor_Test.php
@@ -60,6 +60,159 @@ public function it_should_return_stored_unified_key(): void {
 		$this->assertSame( $key, tribe( Harbor::class )->get_unified_license_key() );
 	}
 
+	/**
+	 * @test
+	 * @dataProvider unified_license_key_provider
+	 */
+	public function it_should_detect_unified_license_keys( string $key, bool $expected ): void {
+		$this->assertSame( $expected, tribe( Harbor::class )->is_unified_license_key( $key ) );
+	}
+
+	public function unified_license_key_provider(): array {
+		return [
+			'prefixed key'              => [ 'LWSW-CUSTOMER-AAAA-BBBB', true ],
+			'prefixed key with spaces'  => [ '  LWSW-CUSTOMER-AAAA-BBBB  ', true ],
+			'legacy product key'        => [ 'abcd-1234-efgh-5678', false ],
+			'empty string'              => [ '', false ],
+			'prefix only substring'     => [ 'my-LWSW-not-a-key', false ],
+		];
+	}
+
+	/**
+	 * When Harbor never fully boots (no premium plugin), unified keys must still
+	 * be rejected from free-plugin PUE fields instead of hitting remote validation.
+	 *
+	 * @test
+	 */
+	public function it_should_reject_unified_key_via_pre_validate_when_harbor_is_not_loaded(): void {
+		global $wp_actions;
+
+		$previous_loaded = $wp_actions['lw_harbor/loaded'] ?? null;
+		unset( $wp_actions['lw_harbor/loaded'] );
+
+		$checker = new \Tribe__PUE__Checker(
+			'deprecated',
+			'the-events-calendar',
+			[],
+			'the-events-calendar/the-events-calendar.php'
+		);
+
+		$result = apply_filters( 'tec_common_pue_pre_validate_key', null, 'LWSW-PASTED-WITHOUT-PREMIUM', $checker );
+
+		if ( null !== $previous_loaded ) {
+			$wp_actions['lw_harbor/loaded'] = $previous_loaded;
+		}
+
+		$this->assertIsArray( $result );
+		$this->assertSame( 0, $result['status'] );
+		$this->assertStringContainsString( 'unified license key', strtolower( $result['message'] ) );
+		$this->assertStringContainsString( 'The Events Calendar Pro', $result['message'] );
+		$this->assertStringContainsString( 'Event Tickets Pro', $result['message'] );
+		$this->assertStringContainsString( 'Unified License Manager', $result['message'] );
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_pass_through_legacy_key_via_pre_validate_when_harbor_is_not_loaded(): void {
+		global $wp_actions;
+
+		$previous_loaded = $wp_actions['lw_harbor/loaded'] ?? null;
+		unset( $wp_actions['lw_harbor/loaded'] );
+
+		$checker = new \Tribe__PUE__Checker(
+			'deprecated',
+			'the-events-calendar',
+			[],
+			'the-events-calendar/the-events-calendar.php'
+		);
+
+		$result = tribe( Harbor::class )->filter_tec_common_pue_pre_validate_key( null, 'legacy-product-key', $checker );
+
+		if ( null !== $previous_loaded ) {
+			$wp_actions['lw_harbor/loaded'] = $previous_loaded;
+		}
+
+		$this->assertNull( $result );
+	}
+
+	/**
+	 * Once Harbor is loaded, the PUE integration owns unified-key messaging;
+	 * this callback must not short-circuit.
+	 *
+	 * @test
+	 */
+	public function it_should_pass_through_unified_key_via_pre_validate_when_harbor_is_loaded(): void {
+		global $wp_actions;
+
+		$previous_loaded = $wp_actions['lw_harbor/loaded'] ?? null;
+		$wp_actions['lw_harbor/loaded'] = 1;
+
+		$checker = new \Tribe__PUE__Checker(
+			'deprecated',
+			'the-events-calendar',
+			[],
+			'the-events-calendar/the-events-calendar.php'
+		);
+
+		$result = tribe( Harbor::class )->filter_tec_common_pue_pre_validate_key( null, 'LWSW-SHOULD-PASS-THROUGH', $checker );
+
+		if ( null !== $previous_loaded ) {
+			$wp_actions['lw_harbor/loaded'] = $previous_loaded;
+		} else {
+			unset( $wp_actions['lw_harbor/loaded'] );
+		}
+
+		$this->assertNull( $result );
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_report_license_field_managed_when_product_is_harbor_licensed(): void {
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$this->assertTrue(
+			tribe( Harbor::class )->is_license_field_managed_by_harbor( 'events-calendar-pro' )
+		);
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_translate_tec_slug_when_checking_license_field_management(): void {
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-promoter' ] );
+
+		$this->assertTrue(
+			tribe( Harbor::class )->is_license_field_managed_by_harbor( 'promoter' )
+		);
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_report_license_field_not_managed_when_product_is_unlicensed(): void {
+		$this->seed_unified_license_key();
+		$this->seed_harbor_catalog_for_tec( [ 'events-calendar-pro' ] );
+
+		$this->assertFalse(
+			tribe( Harbor::class )->is_license_field_managed_by_harbor( 'tribe-filterbar' )
+		);
+	}
+
+	/**
+	 * @test
+	 */
+	public function it_should_include_license_manager_link_in_unified_key_entry_error_message(): void {
+		$message = tribe( Harbor::class )->get_unified_license_key_entry_error_message();
+
+		$this->assertStringContainsString( 'unified license key', strtolower( $message ) );
+		$this->assertStringContainsString( '<a href="', $message );
+		$this->assertStringContainsString( 'Unified License Manager', $message );
+	}
+
 	/**
 	 * @test
 	 */
diff --git a/tests/wpunit/Common/Admin/Custom_List_Table_Test.php b/tests/wpunit/Common/Admin/Custom_List_Table_Test.php
index 2f436a656e..9f735b89c4 100644
--- a/tests/wpunit/Common/Admin/Custom_List_Table_Test.php
+++ b/tests/wpunit/Common/Admin/Custom_List_Table_Test.php
@@ -3,9 +3,12 @@
 namespace TEC\Common\Admin;
 
 use Codeception\TestCase\WPTestCase;
+use Tribe\Tests\Traits\With_Uopz;
 use RuntimeException;
 
 class Custom_List_Table_Test extends WPTestCase {
+	use With_Uopz;
+
 	private static $back_up;
 
 	/**
@@ -17,6 +20,8 @@ public function prepare() {
 		self::$back_up = $wp_actions;
 
 		$wp_actions = [];
+
+		$this->set_fn_return( 'tribe_exit', true );
 	}
 
 	/**