Hello, I am a software developer using Square’s Web Payments SDK to accept online orders on a NextJS application for a client. Right now, I have the payment form set up by following this tutorial.
Recently, customers have been running into issues where they are prompted with the “Enter a valid card number” message, despite their card info being correct.
I have tried my own card and was able to successfully make an order, but I tried my client’s card and it said the card wasn’t valid? Is there any reason for why a valid card number would be declined? This has happened to my client’s card as well as multiple customers.