Invalid codes are being generated from my landing page
If this is happening, check your code file. It should either be a .zip file, or a text file containing your promotion codes (and nothing else), with one per line. Like such:
Check that you have not included any empty lines or any extra text in the file itself.
If there is a problem with your file, simply delete the codes and re-upload.
If you uploaded a .zip file, try extracting the text file inside. Check the file contains only your coupon codes, as above, and try deleting and uploading again.
If your text file is set up right, and the codes are still invalid, try creating new codes in Seller Central. There may be an issue with how the promotion is set up.
If this is the case, check you have followed the correct steps in Amazon Seller Central to create your promotion and single-use promo codes. If necessary, you may have to create a new promotion.
If this doesn’t fix your problem, feel free to contact our support team, and we’ll be happy to help.