JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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.
The best way to do this would be to cancel first your current monthly subscription. You can do this by downgrading your account to "Free": To downgrade your account to free, just follow the instructions provided in this article: How to Downgrade Subscription back to Free Account. This will ensure you are not double billed after signing up for a yearly plan. After you downgrade, the option to upgrade using yearly billing should then be available.
If you encounter any problem, do let us know so we can further assist you.