Check the expiration date of the coupon code to ensure it is still valid. Verify the terms and conditions of the coupon to confirm it applies to the items in the cart. Ensure the code is entered correctly, without any typos or extra spaces. Try using a different web browser or device to see if the issue persists. Clear the browser's cookies and cache to remove any potential conflicts. Disable browser extensions temporarily, as they might interfere with the coupon code. Contact customer service for assistance if the code still doesn't work. Search for a new working promo code if the current one is invalid.
