P23: Currency Discrepancy

Currency discrepancies can happen for a number of reasons, from misconfigured payment terminals to Dynamic Currency Conversion gone sideways. Some merchants are blindsided because everything on their end looked fine. Others had a process gap they didn’t know existed until the dispute showed up. Whatever brought you here, the path forward is the same: find what caused it, build a response if the dispute is worth fighting, and close the door on future occurrences.

I’ll walk through it - the mechanics behind P23, what American Express looks for when you challenge one, and the helpful steps you can take to make sure currency errors stop becoming chargebacks.

What Triggers a P23 Currency Discrepancy Chargeback

A P23 chargeback gets filed when a cardholder is charged in a different currency than the one they agreed to at the time of the transaction. The charge still goes through, but the currency on their statement doesn’t match what they saw at checkout or what they signed for.

The most common cause is Dynamic Currency Conversion, or DCC - a service that lets international cardholders pay in their home currency instead of the merchant’s local currency. But DCC has to be a conscious, well-educated choice - and when it gets applied without consent, or applied incorrectly, a P23 dispute follows.

Terminal misconfiguration is another common culprit. A payment terminal set to the wrong default currency will process transactions in that currency regardless of what the customer expects - this happens at businesses that serve local and international customers and haven’t set up their hardware to manage cleanly.

Manual processing errors also come up more often. When staff enter transactions by hand, it’s easy to choose the wrong currency - especially in environments where multiple currencies are in use at the same time.

International storefronts and multi-currency e-commerce setups add more difficulty. If a customer’s browser or location settings trigger a currency switch automatically and that switch isn’t reflected accurately at checkout and again on the receipt, the door to a dispute is open.

Here is a quick look at the most common triggers behind P23 filings:

Trigger	What Happens
DCC applied without consent	Cardholder is charged in their home currency without agreeing to it
Terminal set to wrong currency	Transactions process in an unintended currency at the point of sale
Manual entry error	Staff selects the wrong currency when keying in a transaction
Auto currency switching online	Storefront changes currency based on location without clear disclosure
Receipt and statement mismatch	The currency shown at checkout differs from what appears on the card statement

The cardholder usually notices when they review their statement and see a charge in a currency they don’t recognize or didn’t agree to. That moment of uncertainty is what starts the dispute process.

The Cardholder’s Right to Dispute and the Filing Window

The Fair Credit Billing Act of 1974 is the foundation for a cardholder’s right to dispute a charge they believe is wrong - it was designed to protect consumers from billing errors, and a currency discrepancy fits squarely into that category. When a cardholder is charged in a different currency compared to what was agreed to at checkout, the law gives them the right to push back.

For American Express P23 disputes specifically, cardholders have as long as 120 days from the transaction date to file. That is a wide window, and it means a transaction from nearly four months ago can still come back as a chargeback. A sale considered closed and settled could reopen without any warning.

That 120-day window is worth taking seriously because merchants move on fast after a sale goes through. By the time a P23 dispute lands, the original transaction might feel like ancient history. Records may be harder to pull together, and the context around the purchase can get fuzzy.

A full understanding of the timeline helps merchants stay prepared instead of scrambling. Here is an overview of the important milestones in a P23 dispute.

Stage	Who It Involves	Time Limit
Cardholder Filing Window	Cardholder submits dispute to Amex	Up to 120 days from transaction date
Merchant Response Window	Merchant submits rebuttal and evidence	20 days from the dispute notification date
Amex Review Period	American Express reviews both sides	Typically 30 to 45 days after merchant response

The merchant response window of 20 days is especially short compared to the cardholder’s filing window. That gap matters because merchants have far less time to act than the cardholder had to initiate the dispute. Having documentation in order before a dispute ever arrives is the only way to respond with confidence inside that tight deadline. Merchants who never reply to a credit card dispute risk an automatic loss, making that preparation even more critical.

How Merchants Can Respond to a P23 Dispute

Merchants get 20 days to respond once a P23 dispute lands in their queue. That window moves fast, and that’s a small business owner who has to dig through transaction logs, receipt archives, and payment processor dashboards all at once.

The response has one thing to do well: show that the cardholder knew the currency before the charge went through. A vague reply that just says “the transaction was valid” will almost never hold up. The evidence needs to be direct and tied to that transaction.

Evidence That Actually Supports Your Case

The strongest rebuttal packages tend to include a few important document types. Here is what processors and card networks look for when reviewing a merchant’s response.

• A timestamped transaction record showing the amount in the charged currency
• A screenshot or log of the checkout screen where the currency was displayed
• A signed receipt or authorization slip that shows the cardholder accepted the amount
• A DCC authorization log if dynamic currency conversion was used
• Any cardholder communication that references the currency or amount

If DCC was involved, the authorization log is especially important - it should show that the cardholder was presented with a choice between currencies and selected the merchant’s currency themselves.

Incomplete submissions are a real problem here. If a merchant sends over a receipt but nothing that shows what the cardholder saw at the point of sale, the network has no way to confirm disclosure happened. That gap in the record tends to go against the merchant.

A shop owner running a small venue or an e-commerce store with one or two staff members does not necessarily have a clean paper trail ready to go. Pulling the right records under a tight deadline is stressful, and the window does not pause while you track things down.

That is why it’s worth saving currency disclosure documentation at the time of sale instead of after a dispute appears. Some payment processors log this automatically, so it’s worth checking what your processor retains and for how long.

Where Currency Errors Actually Slip Through the Cracks

Most merchants believe that if they’ve configured their payment settings once, everything will work correctly from that point on. That assumption is where P23 disputes are born.

The less obvious danger points tend to live inside the tools merchants use without thinking twice. Subscription billing platforms, just to give you an example, sometimes store a customer’s original currency at signup and then charge in a different one after a plan change or a system migration. Third-party payment processors can also introduce a difference between the currency displayed in your storefront and the currency that actually gets submitted to the card network.

Checkout flows that use location detection are another area worth attention. These systems auto-detect a customer’s region and display prices in local currency, which sounds helpful. But if the detection fails or the customer is using a VPN, the displayed currency might not match what gets charged. The customer sees one thing and their bank statement shows another.

The reason these problems persist is simple: merchants test their checkout when they build it, and then they don’t test it again. Running a transaction through the eyes of a customer in Germany, Canada, or Japan is not something most teams schedule into their routine. So a broken currency conversion that only triggers under regional conditions can go unnoticed for months.

Places That Deserve a Closer Look

It’s worth going through your setup with fresh eyes. A few areas that tend to get skipped are listed below.

Area	What to Check
Subscription platforms	Currency stored at signup vs. currency charged at renewal
Third-party processors	Currency passed in the authorization request vs. displayed at checkout
Geo-detection tools	Behavior when location data is missing or incorrect
Post-migration setups	Currency settings carried over correctly after a platform switch
Email receipts and invoices	Currency shown in communications vs. what was actually processed

Email receipts are an easy one to miss. A customer might receive a confirmation showing their local currency while the charge processes in a different one. That mismatch alone is enough to prompt a dispute.

The actual gap is not technical knowledge - it’s that merchants don’t always know which part of their setup to question.

Keeping Your Transactions on the Right Currency Track

A short pre-emptive checklist can go a long way toward keeping P23 off your dispute report:

• Audit your terminal and gateway settings regularly, especially after software updates or processor migrations that can silently reset currency defaults.
• Verify that DCC disclosures are clear and prominent - the cardholder should always know exactly which currency they are agreeing to pay in before they confirm a transaction.
• Test your multi-currency checkout flows using cards from different issuing regions to catch presentation errors that only surface in specific currency contexts.
• Review your receipts and confirmation emails to confirm the currency displayed on your descriptor matches what was actually settled.

Disputes like P23 can seem frustrating exactly because the dollar amounts involved are sometimes small and the cause feels technical instead of intentional. But what the reason code measures - a mismatch between the currency a cardholder agreed to and the one they were charged in - puts you in a strong position to respond, resolve, and avoid. The mechanics are the hardest part to learn. The fixes, in most cases, are well within reach. If you encounter related issues, a cardholder dispute not elsewhere classified template may also be worth reviewing.