Understanding American Express Chargeback Reason Code P23: Currency Discrepancy

American Express Reason Code P23 covers disputes where a transaction was processed in the wrong currency or converted without the cardholder’s consent. It often links to dynamic currency conversion or point-of-sale setup issues. With fast, well-documented responses and clearer currency practices, merchants can limit exposure and protect revenue.

Key Takeaways

• What it means: A transaction was processed in a different currency than agreed, or converted without consent.
• Causes: Merchant error, unapproved dynamic currency conversion, POS configuration issues, or friendly fraud.
• How to respond: Provide proof of the agreed currency, consent to any conversion, or evidence of a refund.
• How to prevent: Make currency options clear. Gain explicit DCC opt-in. Configure systems correctly, train staff, and keep records.

What is an American Express Reason Code P23 Chargeback?

Reason Code P23 is American Express’s label for “Currency Discrepancy.” It arises when a cardholder says the transaction amount was processed in a currency different from the one they agreed to. Or, they claim that a currency conversion took place without their consent. This often appears in cross-border sales, but it can also occur in domestic settings when travellers ask to pay in their home currency.

Dynamic currency conversion (DCC) is a frequent factor. With DCC, the customer can pay in their home currency at the point of sale, with a conversion applied. If you apply DCC without a clear, positive opt-in, the cardholder may later dispute the charge. Some disputes begin as an enquiry, where American Express requests documentation before escalating. If there is enough evidence, the issuer may proceed straight to a chargeback under P23.

In short, P23 signals that the amount debited did not match the agreed currency or that the method of conversion was not approved. Good documentation and clear consent records are often decisive.

Primary Causes for a Code P23 Chargeback

Most P23 cases come down to merchant error. A team member might select the wrong currency at the terminal. An ecommerce site might pass settlement in the wrong currency code. A payment gateway or POS may be configured to a default currency that does not match the cardholder’s choice at checkout. Any of these can produce an amount that differs from the customer’s expectation and triggers a dispute.

Another common cause is using dynamic currency conversion without permission. DCC must be optional, and the cardholder should see the total, the rate, and any fees before they accept. If the customer does not opt in, applying DCC can lead to higher charges and later challenges.

There are also misunderstandings and friendly fraud. A traveller might forget which currency was approved, or assume a mid-market rate applies when the DCC provider uses a different rate. Some cardholders dispute after the fact when they notice a higher total than expected. These causes are preventable with clearer on-screen disclosures, staff training, and accurate settlement practices.

Time Limit for Disputing an American Express Reason Code P23 Chargeback

American Express sets a 20-day time limit for merchants or acquirers to respond to a P23 chargeback. That clock starts when Amex opens the dispute, not when you first read it. Because your acquirer needs time to review and forward the case, your actual window to act may be much shorter, sometimes only a few days.

Late responses are usually disregarded. As a result, it is wise to set internal alerts and workflows that prioritise P23 disputes the moment they arrive. Speed matters, but accuracy matters too. Submitting a partial or disorganised file wastes time. Build a standard pack for currency cases so you can respond well within the time limit. This improves your chance to overturn invalid disputes and protects revenue.

What P23 Means for Consumers & Issuers

P23 protects consumers when an amount charged differs from what they believed they approved. The most common trigger is seeing a statement in an unexpected currency or a total that reflects a conversion they did not authorise. Travellers and cross-border shoppers are most at risk, especially if DCC is applied without a clear, informed choice.

For issuers, P23 flags a compliance and transparency question. The issuer will review whether the merchant processed the transaction in the agreed currency and whether any conversion had clear consent. They may ask for documentation through an enquiry, such as a copy of the receipt, checkout screen capture, or DCC opt-in proof. If the evidence does not resolve the concern, the issuer can raise or uphold the chargeback.

American Express aims to keep outcomes fair. If the cardholder genuinely agreed to the currency or conversion, the issuer may reverse the chargeback after reviewing the merchant’s evidence. If consent is not documented, the dispute is likely to stand.

What P23 Means for Merchants

For merchants, P23 carries operational and financial implications. You may lose the sale, pay fees, and face extra costs tied to international shipping or restocking. Repeated issues can affect your dispute ratio and strain your relationship with your acquirer. Make currency selection explicit, record consent, and settle in the exact currency chosen at checkout.

Point-of-sale and gateway settings need regular reviews. These should be carried out after software updates, terminal swaps, or processor changes. DCC should be optional, off by default, and presented with a clear, simple explanation of the rate and any fees. For in-store sales, printed receipts should show the currency, the exchange rate if used, and the customer’s signature or PIN acceptance of the chosen option. For ecommerce sales, store the checkout screen that shows the currency and the DCC opt-in, along with date and time stamps.

These steps help protect revenue by reducing avoidable disputes and improving your ability to win cases that do arise.

How to Respond to a Code P23 Chargeback

Start by identifying the currency agreed at the point of sale. Pull the order confirmation, the checkout log, the POS journal, or the signed receipt. If DCC was presented and accepted, locate the appropriate proof of consent. 

• E-commerce: A check-box record or a screen capture.
• In-store: A receipt showing the DCC choice, the exchange rate, and the final amount.

Prepare a short cover letter that maps each allegation to your evidence. State the agreed currency. Confirm any opt-in to conversion. Reference supporting documents by filename. Keep the tone factual. Submit within the 20-day window. If your review shows a genuine error, accept the chargeback and correct the cause. If appropriate, contact the customer to explain the fix.

Proactive Prevention: The Ultimate Defence

Prevention begins with clarity. Always present prices and the settlement currency at checkout. If you offer DCC, make it a clear opt-in, show the total in both currencies, and include the rate and any fee. Configure terminals and gateways to prevent unintended conversion. Audit those settings after any updates. Train staff to explain currency options in plain terms and to select the customer’s choice every time. Keep detailed records of receipts, screen captures, and POS logs so you can resolve enquiries quickly. Process credits promptly when due. You can also try out Chargeback.io to get notifications of incoming disputes, giving you the maximum time possible to respond.