What it does
Make a restricted key in Stripe with Write access to Checkout Sessions, and to Webhook Endpoints so payments are confirmed the moment they go through. Formkit refuses your secret key, so it can never do more than open a checkout.
Charge a set amount, the result of one of the form's calculations, or let people pay what they want above a minimum you set.
- How many: one, a number they answered, or picked on Stripe's page
- Promotion codes you made in Stripe
- Stripe Tax, added on top or already in the price
The last button says Pay and send. Stripe's checkout opens, and the answers become a response only once Stripe confirms the payment. If someone leaves without paying, nothing is sent, and the answers are forgotten after two days.
Each response shows what was paid, with how many, any discount and any tax, and exports gain a Payment column. Refunds are made in Stripe, as usual.
How to start
- 1In Stripe, open Developers → API keys → Create restricted key
- 2Give it Write access to Checkout Sessions and Webhook Endpoints
- 3Paste it in a form's Settings → Payments
- 4Set the amount, then Start taking payments
Templates to start from
Every templateGoes well with
In the help centre
- 1 min readTake a payment with a formPeople pay through your own Stripe account as they send the form, and the answers arrive once they have.
- 1 min readCalculations and scoringAdd up answers into a total, a score or a price.
- 1 min readExport to CSV, Excel, JSON or PDFGetting the data out for a spreadsheet, a script or a printer.
Questions
Does Formkit charge a fee on payments?
No. Stripe's own fees apply; Formkit adds nothing.
Can I test it without real money?
Yes. Paste a test key (rk_test_…) and the form takes test payments.
What if I don't want to allow webhooks?
Add one by hand in Stripe and paste its signing secret. Without one, payments are confirmed as people come back and checked every 20 minutes.
Can AI agents fill in a form that takes payment?
No. A form with a payment can't be filled in by an agent, so the agent hands the person the link instead.
Try it on your next form.
Free to start, with unlimited forms, responses and members. See what each plan includes on the pricing page.