Will the participants be charged an additional fee?

I am organizing a race and am willing to pay for the bronze membership.

No, if your form doesn't have any payment fields then it will be treated as a regular submission. For example, you created a registration form and doesn't require your users to pay a registration fee. They will only be charged if you integrate your form to a payment processor.

Please take note that there's no extra charge for each payment submission. We do not take any percentage from your transactions.

Hope that helps. If you have any questions, let us know. Thank you.