ARN Code: What It Is, What It Is Used For and When It Appears in Your Transactions

Posted at 17 Sep 14:09h in Finance

Have you ever made an online purchase and, a few days later, noticed a charge in your account that doesn’t match what you expected? Or requested a refund and found that the money is taking longer than expected to appear? At times like these, a number you have never seen before can become your best ally: the ARN code.

ARN stands for Acquirer Reference Number, and it is essentially a unique identifier assigned to each card transaction when it is processed through the payment network. It is not generated by the merchant or by you as the customer, but by the bank that handles the merchant’s payments. Its purpose is to allow any entity involved (issuing bank, acquiring bank, payment network) to track that specific transaction accurately.

It may seem difficult to understand at first, but don’t worry. In this article, we’ll explain what this code actually is, when it appears in your transactions, what it is really used for and how to request it if you need it.

What Is the ARN Code and Why Does It Exist?

The ARN code is a unique 23-digit number assigned to each credit or debit card transaction made through networks such as Visa and Mastercard. This number is linked to the transaction from the moment the merchant submits the payment until the funds are settled in the cardholder’s account.

It is essentially like a “tracking number” for card payments. Just as a parcel has a tracking code that allows you to see where it is, the ARN allows banks and payment networks to locate a specific transaction within a system that processes millions of operations every day.

This number exists because the payment ecosystem is complex. Keep in mind that the same process involves the merchant, its bank, the payment network (Visa, Mastercard, etc.) and your bank (the institution that issues the transaction). Without a common identifier, tracking a specific transaction would be much slower and more prone to errors. The ARN acts as a bridge between all of them.

When Does the ARN Appear and How Can You Find It?

The ARN does not appear at the exact moment you make a payment. Instead, it appears when the transaction is settled (settlement). In other words, when the merchant’s bank sends the payment to the network so that the movement of funds can be completed. From that moment onwards, the ARN is associated with the transaction and travels with it to your issuing bank.

As a customer, you will not always see the ARN directly in your banking app, but if you need to find it, there are several places where you can look:

  1. In the transaction details: Some banks display it in the expanded transaction information, alongside the date, amount and merchant.
  2. On the statement or receipt: In some cases, it appears as “reference”, “authorization number” or simply “ARN”.
  3. By requesting it from your bank or card issuer: If you cannot see it in the app, you can request it through customer service or online banking. They can look it up in their system because they receive it from the payment network.

If you are a merchant, you will normally find it in your payment gateway dashboard (Stripe, Adyen, Checkout.com…), within the details of each payment or refund.

Where Can You Find the ARN in Your Online Banking?

Let’s start by clarifying that the exact location depends on each bank. However, in many banking apps and websites, the ARN appears on the transaction details screen, sometimes under labels such as:

  • “Transaction reference”
  • “Tracking number”
  • “ARN” or “Acquirer Reference Number”

If you cannot find it, the most straightforward option is to contact your bank and explicitly request the “ARN for the transaction”, providing the date, amount and merchant.

What Is the ARN Really Used For?

The ARN is not designed for you to “verify” a payment in real time in the same way you would track a parcel. However, it becomes extremely useful when something goes wrong. There are three key situations where it is particularly important:

  • Refunds that are taking too long. If a merchant says they have already refunded your money but you cannot see it in your account, the ARN allows your bank to track that refund through the network and confirm whether it is on its way, has been lost or was never sent.
  • Disputes and chargebacks. If you see an unrecognized charge or have a problem with a purchase, the ARN is the main reference that allows your bank to initiate a dispute procedure with Visa or Mastercard. Without this code, the process can be slower and less precise.
  • Reconciliation and auditing. For both merchants and banks, the ARN makes it easier to match transactions across different systems and ensure that every payment and refund has been correctly recorded.

In practice, having the ARN can save you days of back-and-forth when there is an unusual charge or a refund that has not appeared.

Difference Between the ARN and Other Codes You See in Your Transactions

The ARN is not the only code you may see in your bank transactions. You may also come across other reference numbers, and it is easy to confuse them. The ARN is one of several identifiers, but it has a specific purpose. Let’s look at some of the others you may encounter and what makes them different:

  • The ARN is a 23-digit code that identifies a card transaction throughout the payment network, from the merchant’s bank to your bank. It is mainly used by Visa and Mastercard and helps track payments and refunds between different entities.
  • There is also the authorization code, which is generated when the issuing bank approves or declines a transaction. It is usually shorter (6–8 digits) and only indicates that the transaction was authorized at that specific moment, not how it subsequently travelled through the network.
  • Then there is the STAN (System Trace Audit Number), another transaction identifier commonly used by networks such as Discover or in certain point-of-sale systems. It can also be used to track transactions, but it is shorter (6 digits) and is used in different contexts from the ARN. In practice, the ARN is more specific to Visa and Mastercard and more useful for international disputes.

How to Request an ARN from Your Bank or Card Issuer

If you need to request the ARN for a transaction, the process is usually very straightforward. Here are the steps:

  1. Find the transaction in your app or online banking and note the date, amount and merchant.
  2. Check the transaction details. In some banks, the ARN will already appear there under “reference”, “ARN” or a similar label.
  3. Contact your bank. If you cannot see it, write to or call customer service and explicitly request the “ARN for the transaction”, providing those details.
  4. Keep the code together with the purchase or refund receipt, as you may be asked for it if you are dealing with a dispute or claim.

If you are the holder of a card issued by a fintech or digital issuer, the process is quite similar. You can usually request it through the in-app chat or email, and they will send it to you as text or as part of a receipt.

Frequently Asked Questions About the ARN Code

How many digits does an ARN have? 23 numerical digits. It is an international standard format.

Can I generate an ARN myself? No. The payment network generates the code when it processes the transaction. You can only request it from the entity that has it registered (bank, issuer or processor).

Can the ARN be used to dispute fraudulent charges? Yes, it is a key reference in a dispute. With the ARN, the bank can initiate a chargeback procedure with Visa or Mastercard.

How long does an ARN-tracked refund take? It depends on the bank and the type of transaction, but having the ARN can significantly speed up the process. Without it, a refund can remain “lost” for weeks.

Do all cards generate an ARN? All cards operating on international networks (Visa, Mastercard, American Express) do. Prepaid cards that operate on these networks do as well.

The ARN is one of those invisible details of the payment system that only becomes important when something goes wrong. Knowing that it exists, knowing how to request it and understanding what it is used for can save you days of hassle when you encounter an unusual charge or a refund that does not arrive.