What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You can change your credit card details in the My Account / Billing page https://www.jotform.com/myaccount/billing
(click on the images to zoom in)
In the change credit card window, chage your details and hit submit button to save.
Hope this help. Inform us if you need further assistance.