Idempotency in Payment Processing
One of the worst outcomes in payments is charging a customer twice. Idempotency is the technique that guarantees a repeated request has no extra effect, and it is essential to safe billing.
This article explains the concept without the jargon.
The Problem It Solves
Networks are unreliable. A request might succeed but the response gets lost, so your system retries — and without protection, that retry could charge the card again.
How Idempotency Keys Work
- Your system attaches a unique key to each payment request.
- The provider records the result against that key.
- If the same key arrives again, the provider returns the original result instead of charging again.
Why You Can Trust It
This means a customer who double-clicks, or a retry after a dropped connection, never results in a duplicate charge. We use idempotency keys on every payment operation as standard.
Frequently Asked Questions
Does this stop accidental double-clicks too?
Yes. Combined with disabling the button after the first click, idempotency keys make duplicate charges effectively impossible.
If you need a hand with any of this, your Progressive Robot delivery team is ready to help. Raise a ticket from the Support area of your client portal or speak to your account manager and we will guide you through the next steps.