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What is an ARN number

Tuesday, November 11, 2014

What is an ARN Number

If you do business online or regularly accept credit or debit card payments, you may already be familiar with the term “Acquirer Reference Number” or ARN, but what does it mean, and why does it matter for your business?

What’s an ARN?

Every time you make a purchase or sell a product online, a specific number called an ARN is generated. An ARN, or “Acquirer Reference Number,” is a unique number attached to credit card or debit card transactions. This number is also known as a “trace ID” and is generated when a transaction goes from a merchant’s bank account to the cardholder’s bank.

Not to be confused with an Application Reference Number (also abbreviated as ARN), which is a number sometimes used by financial institutions to reference an application for a financial services product.

Now that you’re familiar with the definition of ARN, what does it mean for you as a consumer or business?

What are ARNs used for?

ARNs are typically only relevant when a customer requests a refund or if there’s an error in the transfer of funds from the bank. In these situations, the ARN gives the merchant the ability to track the transaction. You may need access to an ARN for the following:

  • Electronic fund transfers
  • Credit card transactions
  • Debit card transactions
  • Partial settlements
  • Transfer of funds

Being aware of ARNs is especially valuable if your business handles a large volume of transactions each day. While fraud isn’t a guaranteed eventuality, it’s prudent to be mindful of the possibility of fraud with each transaction and monitor the payment flow to detect card schemes early.

How do I find an ARN number?

The process for finding the ARN for a transaction can differ depending on which merchant you use for payment processing. In most situations, you’ll be able to find the ARN in the transaction details. However, since ARNs are assigned by the acquiring bank, you’ll want to check the transaction information available on the acquiring bank’s merchant portal.

The first step for finding an ARN is to check the dashboard of your payment processing portal. Depending on which software you use, the ARN may be displayed with several different statuses, depending on the status of the transaction or refund.

ARNs and refunds

The chances are that if you’re wondering how to find an ARN, you may already have a customer who’s asking for a refund. If a customer is curious about the status of a refund on their Mastercard or Visa purchase, you can provide them with their corresponding ARN code so they can work with their bank to track the status of their funds.

ARNs are particularly useful when a dispute arises. For example, if a client is expecting a refund and there’s an error, delay, or the payment is missing, the ARN can be utilized to trace the refunded transaction. Once the issuer is equipped with this number, the issuing bank should be able to track the status of the refund. Usually, the customer will need to deal with the bank department that handles chargebacks and payment disputes.

When dealing with refunds, it’s a good rule of thumb to clearly state your refund policies in the FAQ section of your website. Then, if you decide that a customer’s request for a refund is valid, the ARN can help protect you both.

How is an ARN different from an STAN?

Both Acquirer Reference Numbers (ARNs) and System Trace Audit Numbers (STANs) can be used to track the status of a refund, but you’ll never need both of these numbers to track a refund.

STANs are similar to ARNs in that they are a unique number generated to identify an individual transaction. However, STANs are trace IDs that are more commonly used internally at the cardholder’s bank to identify transactions.

Another difference between these two numbers is that because STANs are only six-digit numbers, each STAN number is not truly unique since the counter resets after transaction number 999,999. For this reason, ARNs are preferable when a trace ID is needed for a transaction. If an ARN is not available, for non-Mastercard or Visa charges for example, you may have to provide the customer with a STAN.


An ARN is a unique number that’s important for the security of online payments. ARNs prevent fraudulent charges by tracing unauthorized transactions and can give your customers the peace of mind of being able to track the status of their refund throughout the entire process.

Issuing refunds is a part of any business. If your business accepts Visa, Mastercard, or online payments, it’s essential to understand what an ARN is, how to find it, and why it’s crucial to your business.

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