Check the fine print for any exclusions or restrictions on the coupon code. Ensure the code hasn't expired and that it meets all usage limits. Try a different web browser or device to see if the code works there. Disable browser extensions temporarily, as they might interfere with the code. Clear cookies and site data to give the browser a fresh start. Use incognito or private browsing mode to avoid any cached data issues. Contact customer service for assistance if the code still doesn't work. Search for a new working promo code if all else fails.