How can I change the card used for payment on my account?

I upgraded and it auto charged it to a card that is someones who does not work with me anymore. I need to add a card and cannot find where to do it/

You are able to change the credit card in file by going to your billing page: https://www.jotform.com/myaccount/billing 

You should get a pop up asking for your new credit card. 

Let us know if you have any question.