Network
AmexCode
P05Response window
20 calendar daysWin difficulty
MediumDispute type
Processing ErrorAmex P05 — Incorrect Charge Amount: What It Is and How to Respond
20-day deadline: Amex gives merchants only 20 calendar days to respond to P-code disputes. Locate your signed receipt, authorisation record, and order confirmation immediately — these are your entire case for P05.
P05 is filed when the amount settled to the cardholder's account differs from what was authorized or agreed. This includes: settling for more than authorized, manual entry of a wrong amount, a system error changing the amount between authorization and settlement, or a price change applied after the customer confirmed payment.
P05 is one of the more straightforward processing error disputes to assess: either the amount you charged matches what was agreed and authorised (in which case you can contest it), or it doesn't (in which case you should issue a partial refund for the difference and accept the dispute). Your evidence is almost entirely documentary — receipts, authorisation records, and order confirmations.
Common reasons you received this dispute
- 1A tip was added to a restaurant charge after authorisation without obtaining a new authorisation for the total — common with Amex, which enforces tip authorisation rules strictly
- 2A manual transaction entry error where the wrong amount was keyed into the terminal or virtual terminal
- 3A cart or checkout calculation bug that produced the wrong total at the point of payment
- 4A price change applied to an already-authorised order — for example, a price adjustment after checkout confirmation
- 5A settlement amount that differed from the authorisation amount due to a system or batch processing error
Can you win this dispute?
Fight this dispute if...
- ✓The amount charged was correct and matches the signed receipt, authorisation, and what the cardholder agreed to before paying
- ✓The cardholder may be misremembering the price — your documentation clearly shows the agreed amount
- ✓The authorisation amount and settlement amount are identical and match the receipt
Accept this chargeback if...
- ✗The amount was genuinely different from what was agreed — process a partial refund for the difference immediately
- ✗A tip or surcharge was added after authorisation without a new authorisation for the higher total
- ✗Your records show the settlement amount exceeded the authorisation amount
Evidence checklist
- ✅ Required
Signed receipt showing the agreed amount: The receipt signed by the cardholder showing the total amount. This is the definitive record of what the cardholder agreed to pay.
- ✅ Required
Authorisation record matching the settlement amount: The authorisation your system obtained, showing the authorised amount is equal to the amount settled. A mismatch between these two amounts is the core of a P05 dispute — demonstrate they are the same.
- ⭐ Strongly recommended
Order confirmation email showing the price before payment: The confirmation the cardholder received before paying, showing the price they saw at the time of purchase. This closes the loop between what was displayed, what was agreed, and what was charged.
How to prevent this chargeback
- 1
Show the total on screen before the cardholder taps or chips (card-present): Always display the complete charge amount — including any tips, surcharges, or service fees — on the terminal screen before the cardholder authorises. The cardholder must see and confirm the exact amount.
- 2
Never add tips or extras without a new authorisation: For restaurants and hospitality: if a tip is added after initial authorisation, obtain a new authorisation for the full amount including the tip. Settling for more than the original authorisation amount is a straightforward P05.
- 3
Reconcile cart totals before displaying the final payment confirmation (e-commerce): Run a server-side total calculation immediately before displaying the payment confirmation screen. Never rely solely on client-side totals, which can be manipulated or miscalculated.
Frequently asked questions
What is Amex P05?
Amex P05 is filed when the amount settled to the cardholder's account differs from what was authorized or agreed. This includes settling for more than authorized, a manual entry of a wrong amount, a system error that changed the amount between authorization and settlement, or a price change applied after the customer confirmed payment.
How does P05 differ from P03 and P04?
P03 and P04 are about the wrong transaction type — a credit processed as a charge or vice versa. P05 is purely about the amount: the transaction type was correct (it was a charge) but the amount charged was different from what was authorised or agreed. P05 may be filed for overcharges, undercharges, or unauthorized price additions like tips added without re-authorisation.
What evidence wins a P05 dispute?
The core evidence package for P05 is: a signed receipt showing the agreed amount, an authorization record that matches the settlement amount, and an order confirmation email showing the price the customer saw before paying. All three amounts must match. If they do, and the cardholder is simply misremembering the price, you have strong grounds to contest.
What are the tip authorization rules for restaurants that commonly trigger P05?
For Amex, adding a tip after the initial authorization without obtaining a new authorization for the total amount is a common P05 trigger. The correct process is to either: (1) obtain authorization for the estimated total including tip, or (2) obtain a new authorization for the full amount once the tip is added. Settling for more than the authorized amount — even by a tip — can trigger P05.
Related reason codes
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