thread Re: Credit Card Payment: Card nonce already used with a different idempotency key; in Payments Troubleshooting

Square + Gravity Integration Error: "Card nonce already used with a different idempotency key"

sdewitti — Sat, 20 Sep 2025 07:41:35 GMT

The title of this thread has been edited by a Square Moderator from the original: "Credit Card Payment: Card nonce already used with a different idempotency key;"

After using SQUARE for year through Gravity forms recently I started seeing an issue. Users on my site see the error below and then try again and the order goes through twice. This is new and I have not changed anything that I am aware of.

Credit Card Payment: Card nonce already used with a different idempotency key;

Any ideas?

Re: Credit Card Payment: Card nonce already used with a different idempotency key;

TheRealChipA — Sun, 19 May 2024 14:46:35 GMT

Hey @sdewitti. You’re not the first Gravity Forms user to see this. There are a number of posts on Gravity’s help forum about it. Here’s a link to one that seems to have a solution. That poster determined this was not a Square issue but rather a Gravity settings issue. I have no clue what changed, where it changed, or why it changed. But this seems to be a/the solution. If it doesn’t work, there are other threads in Gravity about this subject, too. Good luck.

Re: Credit Card Payment: Card nonce already used with a different idempotency key;

TheRealChipA — Sun, 19 May 2024 14:48:31 GMT

@sdewitti That link I posted is slightly different, but it is about nonse issues. It seems too similar to be a coincidence. I hope it helps.

Re: Square + Gravity Integration Error: "Card nonce already used with a different idempotency k

sdewitti — Tue, 21 May 2024 21:33:27 GMT

Yeah, that solution does not make sense. I am trying to correct this but it is so inconsistent in when it happens.

Re: Square + Gravity Integration Error: "Card nonce already used with a different idempotency k

_Violet — Tue, 21 May 2024 21:41:07 GMT

Hi there, @sdewitti - I appreciate you reaching out to us regarding this issue. I can certainly point you in the right direction to get this resolved as soon as possible. Although Square integrates with Gravity Forms, the integration is operated and managed by Gravity. For help with Gravity-specific questions, you’ll need to submit a ticket to their Support Team.

I hope this information is helpful but please do let me know if you have any additional questions.