What is an Acquirer Reference Number (ARN)?

Waiting for a refund that never seems to arrive, or spotted a card transaction you don’t recognise? Understanding how to trace payments can feel unclear without the right tools.

In this guide, we’ve explained what an Acquirer Reference Number (ARN) is, how it works, and the exact steps UK residents can take to track transactions, resolve disputes, and follow up on delayed payments.

We’ve also explained how you Wise Business an help simplify transaction management and provide clearer visibility and control over your business finances.

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Key Takeaways

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What is an acquirer reference number (ARN)?

An Acquirer Reference Number (ARN) is a unique identifier assigned to a credit or debit card transaction by the merchant’s bank (the acquiring bank)². It functions as a tracking reference across card payment networks.

When a payment is made, it travels between the issuing bank (your bank) and the acquiring bank (the merchant’s bank). The ARN is generated during this process and is typically a long numeric code used to identify that specific transaction².

The ARN allows banks to trace the movement and status of a transaction, particularly in cases such as refunds or disputes³.

Why you might need an ARN number in the UK

For UK residents, there are several scenarios where an ARN can be useful.

Tracking a delayed refund

If a refund has been issued but hasn’t appeared in your account, an ARN can help your bank locate the transaction within the card network¹.

Disputing an unrecognised transaction

If you notice a charge you don’t recognise, your bank may use the ARN to investigate the transaction with the merchant’s bank².

Following up on failed or complex payments

For certain payments, particularly international ones, an ARN can help banks identify where a transaction may have been delayed or interrupted³.

Providing proof of payment

An ARN can act as evidence that a payment has been processed through the banking system³.

How to get an ARN number in the UK

You cannot usually access an ARN directly yourself. Instead, you need to request it.

1. Identify the transaction

Locate the transaction details, including date, amount, and merchant name.

2. Contact your bank or card issuer

Your bank is typically your first point of contact for requesting an ARN.

3. Request the ARN

Ask your bank to trace the transaction and provide the ARN. In some cases, a merchant may supply it for refunds¹.

4. Wait for confirmation

Depending on the case, retrieving the ARN may take a few business days.

The role of the bank and card issuer in ARN transactions

The acquiring bank generates the ARN when processing a payment². This reference is then shared across the card network and accessible to the issuing bank.

Your bank acts as your primary contact and communicates with other institutions to trace transactions using the ARN³.

Understanding ARN number tracking and dispute resolution

An ARN allows banks to track transactions across systems.

For example, when tracing a refund, your bank can use the ARN to check whether it has been processed and when it may arrive¹.

In disputes such as chargebacks, the ARN is used as the main reference between financial institutions to ensure accurate communication about the transaction².

Clarifying ARN numbers against other references

Payment gateway IDs (e.g. Stripe or PayPal) are also internal references and are not the same as an ARN, although merchants may use them to locate the ARN³.

Manage Business Transactions with Greater Clarity Using Wise

For businesses handling multiple payments across currencies, tracking transactions can become complex without the right tools.

Wise Business offers a way to manage international payments with low, transaparent fees on currency conversions.

With Wise Business, you can:

• 🌍 Send money to 140+ countries at the mid-market exchange rate with no hidden fees or sneaky exchange rate markups (product availability varies by region; please check the Wise website for local availability)

• 📥 Receive payments in 24 currencies and counting

• 💵 Get local account details for 8+ currencies, including USD and EUR, to let your customers pay in a currency they know and trust - convenience for them and peace of mind for you.

• 💰 Hold money in 40+ currencies

• ⚡ Use the batch payments tool to create and send up to 1,000 payments in a single transfer

• 👥 Run payroll and make international payments for up to 1,000 employees all over the world

• 💳 Get business debit cards with 0.5% cashback for you and your team to keep track of team expenses and spend all over the world

• 🏢 Manage cash in 55+ currencies across international offices from a single business account and move money between business accounts in seconds (exact speeds can vary depending on individual circumstances and may not be the same for all transactions)

• 🔄 Connect and sync every business transaction to your favourite accounting software, including Xero, Quickbooks, and more

• 🔐 Create your own payment approvals process to manage your team better with customised access for different team members

• 📑 Create custom professional invoices and schedule invoice payments for future dates

• 📈 Earn returns on GBP, USD and EUR with Wise Interest (Capital at risk, growth not guaranteed. Your money is at risk if governments default or interest rates go negative. Visit https://wise.com/gb/interest/ to find out more)

• 🔗 Create payment links and QR codes to get paid easily

• ⚙️ Automate payouts with the Wise API (comes with 24/7 customer support, a sandbox account to test integrations, API tokens, and clear documents on how to implement and make the most of our API)

Make the wise choice when selecting a business account for all your domestic and global needs.

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Register for Wise Business ✍️

*Disclaimer: The UK Wise Business pricing structure is changing with effect from 26/11/2025 date. Receiving money, direct debits and getting paid features are not available with the Essential Plan which you can open for free. Pay a one-time set up fee of £50 to unlock Advanced features including account details to receive payments in 22+ currencies or 8+ currencies for non-swift payments. You’ll also get access to our invoice generating tool, payment links, QuickPay QR codes and the ability to set up direct debits all within one account. Please check our website for the latest pricing information.

FAQs

Can I track an ARN myself online?

No. There are no public tools to track an ARN. Only your bank can trace it through card networks¹.

What does it mean if an ARN cannot be found?

It may indicate the refund or transaction has not been fully processed yet, or that further investigation is required by your bank¹.

Is an ARN the same for debit and credit cards?

Yes. The ARN system works the same way for both debit and credit card transactions¹.

Can merchants see or provide an ARN?

Yes. Merchants can often access the ARN via their payment provider and share it with you for tracking purposes³.

Sources:

1. What is an ARN? - Checkout.com
2. What is an Acquirer Reference Number? - emerchantpay
3. What is an ARN number? - Airwallex UK

Sources last checked on April 2026