Amex Reason Code C18: No Reply to Inquiry — Cancelled Recurring

What Amex Reason Code C18 Means

Amex reason code C18 is titled No Reply to Inquiry — Cancelled Recurring. It is a procedural escalation code, not a direct cardholder dispute. The sequence is: a cardholder filed a dispute about a recurring charge they claim was cancelled; Amex sent your business an inquiry requesting documentation; you did not respond within the required window; Amex escalated the inquiry to a formal chargeback using code C18.

Unlike most chargeback codes where the dispute goes directly to the chargeback stage, Amex's inquiry process is a first-line resolution mechanism. Responding to inquiries promptly — before they become chargebacks — is the most effective way to manage C18 exposure. Once the inquiry becomes a C18 chargeback, you are fighting on two fronts: the procedural failure and the underlying dispute.

Cross-Network Equivalent Codes

Common Trigger Scenarios

• Inquiry notification missed by merchant. The Amex inquiry was received by your processor but not forwarded to you in time, or was routed to an email inbox that wasn't monitored. By the time anyone saw it, the 20-day window had passed and the C18 chargeback had already been filed.
• Inquiry received but deprioritized. Staff received the inquiry but treated it as low priority, intending to respond later. The deadline passed before a response was submitted. Inquiries are not low priority — they are your first and best opportunity to resolve a dispute without a chargeback.
• Recurring charge after confirmed cancellation. The underlying dispute is valid: the cardholder did cancel, the cancellation was processed, but a subsequent charge went through anyway due to a billing system error. The merchant's silence at the inquiry stage converted this into a C18.
• Cancellation request not processed by merchant system. The cardholder cancelled via email, phone, or account portal, but the cancellation was not properly recorded in the billing system. The charge continued, the cardholder disputed, and the inquiry went unanswered.
• Free trial auto-converted to paid without cardholder awareness. A free trial automatically converted to a paid subscription. The cardholder filed a cancelled recurring dispute. The inquiry arrived, went unanswered, and escalated to C18.

Key Deadlines & Timeframes

Evidence You Will Need

You cannot undo the missed inquiry deadline, but you can fight the underlying cancelled recurring dispute on its merits. Gather the same documentation you would have provided at the inquiry stage.

• Subscription or recurring billing agreement showing the cardholder enrolled in recurring billing and the terms of the subscription, including cancellation requirements
• Cancellation policy as it existed at the time of enrollment and at the time the cardholder claims to have cancelled — showing the required cancellation process
• Cancellation request records (or lack thereof) — if the cardholder did not cancel through your required process, show that no valid cancellation was received in your system before the disputed charge
• Service delivery confirmation showing the subscription service was active and accessible to the cardholder during the disputed billing period
• Customer service communication records showing any prior interaction about the cancellation request, including whether it was accepted or why it was declined
• If cancellation was received: the date it was processed and confirmation that no further charges were applied after that date

How Merchants Lose This Dispute

• Missing the inquiry deadline in the first place. Every C18 represents a missed inquiry. Merchants who build inquiry monitoring into their daily operations eliminate C18 chargebacks at the root. Set up inquiry alerts at the processor level and designate a specific person responsible for responding.
• Fighting the procedure rather than the merits. Arguing that you should have received more time or that the inquiry was forwarded late does not resolve the underlying dispute. Address the substance of the cancelled recurring claim directly.
• No clear cancellation policy or procedure in your system. If your cancellation process is undefined or your subscription platform does not log cancellation requests with timestamps, you cannot demonstrate whether a valid cancellation was submitted before the disputed charge.
• Charging after a documented cancellation. If your records show a cancellation was processed and you charged the cardholder anyway due to a billing system lag or error, the chargeback is valid regardless of procedure. Issue the refund and fix the billing system.

Response Framework Overview

1. Acknowledge the procedural context briefly. You do not need to dwell on the missed inquiry — focus on the merits of the underlying dispute.
2. Present the subscription agreement. Show the cardholder enrolled in recurring billing and the terms, including the cancellation policy they agreed to.
3. Address the cancellation claim directly. Either show no valid cancellation was received before the disputed charge, or show the cancellation was processed and no further charges were applied.
4. Demonstrate service was delivered. Show the subscription service was active and accessible to the cardholder during the disputed billing period.
5. Reference any customer service interactions. If the cardholder contacted you about cancellation and you responded, include that communication.

Prevention Tips

• Respond to every Amex inquiry within 7 days, not 20. The 20-day window is the outer limit. Processor forwarding delays and internal routing can eat into that window quickly. A 7-day internal response target eliminates C18 exposure entirely.
• Designate a specific person to own inquiry management. Inquiries that land in a general inbox or get forwarded without clear ownership routinely go unanswered. One person or team should own inquiry monitoring and response as a dedicated function.
• Honor cancellation requests immediately. Process cancellations in your billing system the same day they are received, regardless of channel. Delayed cancellation processing is the primary source of the underlying dispute that generates the inquiry in the first place.
• Send cancellation confirmation emails. Confirm every cancellation with an automated email showing the cancellation date and confirmation that no further charges will occur. Cardholders who receive clear cancellation confirmation rarely dispute recurring charges.

Frequently Asked Questions

What is the difference between Amex C18 and C28?

Code C28 is a direct chargeback filed when a cardholder claims they cancelled a recurring billing arrangement. Code C18 is a procedural escalation — Amex sent an inquiry, you did not respond within the required timeframe, and Amex automatically converted it to a chargeback. C18 disputes are harder to win because the procedural failure is itself a problem.

What is an Amex inquiry and how does it differ from a chargeback?

An Amex inquiry is a preliminary information request sent before a formal chargeback. Amex gives merchants about 20 days to respond with documentation. If you respond and resolve the issue, no chargeback is filed. If you miss the deadline, Amex escalates to a C18 chargeback automatically.

Can I win a C18 chargeback?

C18 disputes are difficult to win because they reflect a procedural failure. However, you can still fight the underlying dispute by responding with cancellation records, subscription terms, and service delivery proof. You cannot undo the missed inquiry, but you can win on the merits of the underlying cancelled recurring claim.

How long does Amex give merchants to respond to inquiries?

Amex typically gives merchants 20 days to respond to an inquiry before escalating to a chargeback. However, processor forwarding delays can reduce your effective window. Treat all Amex inquiries as urgent and respond within 7 days to ensure you never miss the deadline.

Related Codes & Resources