American Express · Chargeback reason codes
American Express C18 chargeback: Guaranteed Reservation or Advance Deposit
Checked
American Express reason code C18, Cardmember Incorrectly Billed for Guaranteed Reservation or Advance Deposit, means the Cardmember says they cancelled a reservation or deposit and were charged anyway. The issuer waits 15 days from the cancellation before filing. Win with proof a credit was given, the cancellation policy and how it was broken, or other proof that the reservation or deposit charge was valid.
- Category
- Cardmember dispute
- Time limit for the bank to file
- Usually 120 days from the network processing date
- Time limit to respond
- 20 days from the Amex chargeback or inquiry in the US (your processor's deadline may be earlier); no reply means a "No Reply" chargeback
- Typical evidence
- Cancellation policy and how it was broken; proof the reservation was valid
- Can it be prevented?
- Yes: clear cancellation terms and cancellation numbers
- Who usually wins
- The merchant with a disclosed policy the Cardmember broke
What PlatformDTC does
For a "refund not received" dispute, PlatformDTC reads the refund history from Stripe: if the money was already returned it sends each refund's amount, date and acquirer reference number (ARN) and asks the bank not to pay twice; if not, it quotes the store's published refund policy. With "Answer a chargeback automatically" switched on, it sends the response to the bank for you before the deadline.
What it means
A no-show or advance deposit charge for a reservation the Cardmember says they cancelled.
Why customers file it
Cancellations that were not recorded, or that fell outside the cancellation window.
Evidence that wins
For every Amex code, a credit that directly offsets the disputed charge is also an accepted response.
- Proof of a credit processed
- The receipt or cancellation policy and how the Cardmember did not follow it
- Other proof the reservation or deposit was valid
How to prevent it
- Disclose cancellation terms at booking
- Give a cancellation number for every cancellation
For developers
On Stripe the dispute object arrives with reason "credit_not_processed" and the card network's own code in payment_method_details.card.network_reason_code; listen for charge.dispute.created and read evidence_details.due_by for the deadline.
American Express uses one letter plus two digits for US and Canada merchants; elsewhere it uses four-digit ISO codes, and each letter code sits under one.
Frequently asked questions
- Does C18 apply to online stores?
- It applies to guaranteed reservations and advance deposits, such as lodging; an ordinary product order uses other codes.
- How long must the bank wait?
- 15 days from the cancellation.
Sources
Related
- C05 — The Cardmember cancelled the order or service and did not get a credit.
- C02 — The Cardmember says a credit you owed them never reached their account.
- C28 — The Cardmember says a subscription kept billing after they cancelled.
- C31 — The Cardmember says the goods or services did not match the description or quality promised.
- C32 — The Cardmember says the goods arrived damaged or defective.
- M10 — The Cardmember disputes a car rental charge for damage, theft or loss of use.
- F29 — The Cardmember says they did not make an online, phone or mail order purchase.
- F10 — The Cardmember denies an in-person charge and there is no card imprint or swipe record.