I know there is a fee if we have more than 10 registrations in a month. How do I arrange to pay you the fee?

As a free user you have 100 submission, 10 SSL Secure Submissions and 10 Receive Payments.

If you reach your monthly limit your forms will be disabled and unavailable for use by visitors. If you reach your monthly limit you can wait for the next month when your submissions counter resets or upgrade your account.

If you need more submissions you can subscribe to paid plan. 

Hope this will help. Let us know if you need further assistance.