# ARN (acquirer reference number)

https://www.uniwebpay.com/glossary/arn/

*Last updated: 2026-08-03*

The identifier a transaction carries through the scheme network, used to trace one specific payment or refund between the acquirer and the issuer. It is what a merchant is asked for when a customer says a refund never arrived: with it, the customer's own bank can find the money.

## Why it matters to a merchant

Ask for it the first time a customer says a refund has not arrived, rather than the third. Nine times in ten the refund was processed and is sitting somewhere the customer has not looked; with this number their own bank can find it in minutes, and without it the conversation goes in circles for a week.

## Related terms

*How a payment moves*

- [Authorisation](https://www.uniwebpay.com/glossary/authorisation/)
- [Capture](https://www.uniwebpay.com/glossary/capture/)
- [Settlement](https://www.uniwebpay.com/glossary/settlement/)
- [T+1 settlement](https://www.uniwebpay.com/glossary/t-plus-1/)
- [Batch](https://www.uniwebpay.com/glossary/batch/)
- [Reconciliation](https://www.uniwebpay.com/glossary/reconciliation/)
- [Chargeback](https://www.uniwebpay.com/glossary/chargeback/)
- [Refund vs void](https://www.uniwebpay.com/glossary/refund-void/)
- [Pre-authorisation (hold)](https://www.uniwebpay.com/glossary/pre-authorisation/)
- [Issuer decline](https://www.uniwebpay.com/glossary/issuer-decline/)
- [Merchant descriptor](https://www.uniwebpay.com/glossary/merchant-descriptor/)
- [3-D Secure](https://www.uniwebpay.com/glossary/three-d-secure/)
- [Tokenisation](https://www.uniwebpay.com/glossary/tokenisation/)
- [Card on file](https://www.uniwebpay.com/glossary/card-on-file/)
- [Payment link](https://www.uniwebpay.com/glossary/payment-link/)
- [Representment](https://www.uniwebpay.com/glossary/representment/)
- [Chargeback ratio](https://www.uniwebpay.com/glossary/chargeback-ratio/)

- [All 74 terms](https://www.uniwebpay.com/glossary/)

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