What is an Acquirer Reference Number (ARN)? 

An Acquirer Reference Number (ARN) is a unique 23-digit code used for Visa and Mastercard payments. ARN lets merchants, banks and customers securely track transactions and refunds across the payment network.

In this article, we’ll take you through what ARNs mean, how to locate them, what their uses are and how they can benefit your business.

What is an ARN number and how does it work?

ARN stands for Acquirer Reference Number and is a unique 23-digit number assigned to every Visa and Mastercard card transaction processed online. The first digit of this number will tell you what card scheme was used for the payment; this will be a ‘7’ for Visa or an ‘8’ or a ‘2’ for Mastercard transactions. Then, the next six to eight digits after this are the acquirer’s Bank Identification Number (BIN). Basically, the ARN number helps trace and reconcile a payment during the payment process.

Once a customer has initiated a payment online, the payment data is securely transferred from the payment gateway to the acquirer. After the acquirer has authenticated the payment, they then encrypt this data and create an ARN number before passing the payment information on to the issuer to authorise. The ARN will then be used to track the payment as it moves through each stage of the payment journey, from authorisation to settlement. While ARNs provide greater oversight of the payment process for merchants, they can also be used to track customer refunds and help resolve chargebacks.

What are ARNs used for?

ARNs are primarily used to track and reconcile transactions as they move through the payment ecosystem. They ensure that each card payment can be uniquely identified and followed from authorisation all the way to settlement.

ARNs are essential for transparency and trust in the payments ecosystem. With 27.76 billion payment cards in circulation in 2024 and forecasts of 31.13 billion by 2029, billions of transactions are processed every day. Without a reliable way to trace them, resolving disputes and tracking refunds would be almost impossible.

For merchants, ARNs provide clarity and oversight of the payment process. They make it easier to:

Confirm settlement of transactions: Merchants can see when a payment has been successfully processed and the funds have been credited to their account.
Track refunds: ARNs allow merchants and customers to monitor the status of a refund and understand when funds will be returned.
Resolve disputes and chargebacks: By serving as a reference point, ARNs help speed up investigations and provide evidence to issuers or card schemes.
Increase transparency for customers: Sharing an ARN with a customer helps reassure them that their refund request is progressing.

How to find your ARN number?

Here’s how you can find your ARN in emerchantpay’s payment platform:

Log in to your dashboard.
Go to Payment Transactions.
Select the Payment Transactions tab.
Go to Customisable Columns and select ARN under the list of options.

After applying this change, you’ll now be able to see the ARN for each transaction on the emerchantpay dashboard.

Step by step guide to track a refund with an ARN

Merchants can use this step by step guide to trace a bank refund using the Acquirer Reference Number.

Locate the ARN
Collect the supporting details - In addition to the ARN, you will need to locate the transaction ID, order reference, refund amount, date of the original payment, date the refund was requested, card last four digits and the customer name. A screenshot of the transaction can also help.
Send the ARN and details to your payment service provider (PSP) or acquirer - Contact your PSP via their support portal, your merchant dashboard ticketing tool or their authorised support email. Put the ARN and the supporting details in your request so the team can run a trace promptly.
What your PSP will do next - The PSP will use the ARN to ask the acquirer and card schemes to locate the refund as it moves through the payment network. If the refund does not yet appear in the scheme’s or issuer’s system, the PSP may open an investigation with the scheme to clarify its status and confirm when the funds will reach the customer.
How to interpret status updates - ARN is processing Meaning: the refund has been initiated but has not yet been completed through the scheme or issuer. Action: ask the PSP to confirm which stage the refund is at and to escalate with the scheme or issuer if needed. Keep the ARN and any case reference in your records. ARN is available Meaning: the scheme has recorded the refund and the ARN is complete. Action: request the PSP’s refund details and share the ARN with the customer so they can quote it to their card issuer if their bank needs it. ARN is unavailable Meaning: the refund did not progress, for example, because the original charge was reversed before settlement or the refund was attempted too early. Action: ask the PSP to explain whether the original authorisation was reversed or whether a fresh refund should be issued. Record the outcome.
Update the customer - Clearly tell the customer you have the ARN, explain what the status means and what you and your PSP are doing. Provide the ARN and any case reference so the customer can follow up with their bank if they choose to do so.
Record keeping and escalation - Save the ARN alongside the order and refund notes for future reference. If the PSP and issuer cannot locate the funds, work with your PSP to escalate the case to the card scheme using the ARN and any investigation reference numbers.

Common issues with ARNs and how to resolve them

While ARNs are designed to make transaction tracking straightforward, there are a few common issues that merchants and customers may encounter:

Bank or issuer cannot locate the ARN: Sometimes a refund or payment trace fails because the bank or issuer cannot find the ARN in their system. This can happen if the ARN was generated incorrectly, if the original payment has not fully settled or if the refund was attempted too early. Resolution: Contact your payment service provider with the ARN, transaction details and date of the original payment. Your PSP can liaise with the acquirer or card scheme to clarify the status and provide guidance on the next steps.
Refund delays despite a valid ARN: Even with the correct ARN, refunds can take longer than expected due to processing times at the card scheme or issuing bank. Resolution: Share the ARN with the customer and explain the expected timeframe. Use your PSP to track progress and provide updates at each stage.
ARN shows as unavailable: This occurs when a refund is attempted before the original payment is fully processed or if the original transaction is reversed. Resolution: Confirm with your PSP whether a new refund needs to be issued or if the original reversal has already resolved the payment.
Mismatch between ARN and transaction details: Occasionally, an ARN may not match the expected transaction in the merchant dashboard, often due to duplicate entries or manual errors. Resolution: Cross-check order numbers, transaction IDs and payment dates. Escalate to your PSP if discrepancies persist.

By understanding these common errors and knowing how to address them, merchants can maintain transparency with customers, minimise confusion and ensure that refunds and payment traces are handled efficiently.

What are the benefits of ARNs?

ARNs are an essential component of the online payments landscape and they carry their own set of benefits for merchants. Below, we outline some of the most common ones.

Reduced fraud

By assigning a unique identifier to each transaction, merchants can leverage ARNs to track payments and detect any suspicious transaction activity. As this process can help trace any unauthorised transactions and deter fraudulent payments from being processed, the threat of fraud can be significantly minimised.

Increased efficiency

ARNs are instrumental in identifying and monitoring transactions. They serve as a distinctive number assigned to each individual transaction, which can help gain visibility of the payment’s journey from the merchant’s business account to the customer’s bank account. This can help reduce the risk of errors and discrepancies.

Faster dispute resolution

In the case of disputes or chargebacks, ARNs can act as reference points. This means that ARNs can support businesses in providing evidence about the validity of a transaction to address any issues with cardholders and issuers. This can result in faster dispute resolution.

Differences between ARNs, STANs and RRNs and when to use them

In the payments ecosystem, ARNs are not the only identifiers used to track transactions. You may also come across STANs (System Trace Audit Numbers) and RRNs (Retrieval Reference Numbers). Each serves a specific purpose and knowing the differences can help merchants and customers resolve issues more efficiently.

ARN (Acquirer Reference Number)

A 23-digit number generated by the acquirer for Visa and Mastercard transactions.
Used to track a transaction or refund as it moves through the card scheme and issuing bank.
Best used when a customer wants to trace a payment or refund through the full processing flow.

STAN (System Trace Audit Number)

A six-digit number assigned by the payment processor when a transaction is initiated.
Mainly used internally by processors to identify and reconcile transactions in their own systems.
Helpful for acquirers or PSPs, but less useful for merchants or customers, as it does not follow the transaction across the entire network.

RRN (Retrieval Reference Number)

A 12-digit number issued by the acquiring bank.
Commonly used to identify a transaction during dispute handling, such as a chargeback or retrieval request.
Useful for merchants when responding to issuer queries or disputes.

When should customers use them?

Customers waiting on a refund should ask for the ARN, as this will show the progress of funds through the banking system.
Merchants dealing with a dispute or chargeback may be asked to provide the RRN to help resolve the case.
STANs are generally not shared with customers, as they are most relevant for processors and acquirers.

In short, ARNs provide visibility for customers, RRNs support dispute management and STANs are mainly for internal reconciliation. Together, these identifiers ensure transparency and accountability in the transaction journey.

FAQs

How long does a refund take after the customer receives the ARN?

Refund times vary by card scheme and issuing bank; funds may take from a few minutes to up to 10 business days to reach customers. From late 2025, Visa and Mastercard will mandate real-time refund authorisation to speed up returns, though actual timelines will still depend on each issuer’s readiness, so processing speeds may differ during rollout. funds may take from a few minutes to up to 10 business days to reach customers. From late 2025, Visa and Mastercard will mandate real-time refund authorisation to speed up returns, though actual timelines will still depend on each issuer’s readiness, so processing speeds may differ during rollout.

Who generates ARNs?

ARNs are created by the acquirer once a Visa or Mastercard transaction or refund has been processed. They are then passed to your payment service provider so you can view them in your merchant dashboard.

Can ARNs be used to trace international refunds?

Yes. ARNs work across borders for Visa and Mastercard transactions because they are scheme-wide identifiers. This means that merchants can use the same ARN to trace a refund, whether the customer’s bank is domestic or overseas.

Do ARNs expire?

No. Once generated, an ARN remains linked to the original transaction. Even months later, merchants can use it to trace or provide evidence of the payment or refund, which is especially helpful for disputes raised after some time.

Are ARNs available for partial refunds?

Yes. Each partial refund processed on a transaction will have its own ARN. This allows merchants and customers to track each refund separately if multiple credits are issued against one original payment.

No. An ARN does not contain card data and cannot be used to initiate a transaction. It is safe to share with a customer so they can follow up with their bank.

How do ARNs work with chargebacks?

While ARNs themselves do not prevent chargebacks, they can provide a clear audit trail that speeds up investigations and helps merchants supply evidence to issuers during dispute resolution.

Are ARNs issued for all payment methods?

No. ARNs are specific to Visa and Mastercard card payments. Alternative payment methods, such as bank transfers or digital wallets, have their own identifiers and cannot be tracked with an ARN.

How emerchantpay can help

ARNs might seem like a set of digits, but they can facilitate secure and trustworthy transactions. While they can help merchants prevent fraud, customers are given peace of mind and expedited dispute resolution, if necessary.

At emerchantpay, we take pride in our extensive global payment solution, which encompasses a wide range of features. This includes global acquiring, robust fraud and risk management and a host of other capabilities. Our knowledgeable team is here to offer tailored support, guiding you on how to optimise your payment processes for improved payments performance and profitability.

Ready to learn how emerchantpay can support you in increasing your payments efficiency for maximised revenue? Contact our team of payment specialists today.