Billing: How can I change my monthly plan to an annual plan.

You can change your subscription from a monthly to an annual plan by going to the billing tab of your My Account page:

https://www.jotform.com/myaccount/billing

Once there, simply click on the plan you would like to use, which in your case is Gold, and select Yearly as its desired Payment Schedule, as depicted in the following image:

You will be switched to that plan.

Please let us know should you need any further assistance.