An Agency Debit Memo (ADM) is a formal notice issued by an airline to a travel agency through the BSP (Billing and Settlement Plan) or ARC (Airlines Reporting Corporation) system. It is used when an airline detects an error, rule violation or financial discrepancy in a ticket that was issued by the agency. In simple terms, it’s like an invoice or penalty that corrects mistakes in ticketing or fare application.

Why ADMs are issued (common reasons)

• Incorrect fare calculation or wrong ticketing.
• Misuse of airline booking rules or fare conditions.
• Under collection of taxes, surcharges or fees.
• Duplicate or fraudulent ticket issuance.
• Incorrect refunds or exchanges.

Impact of ADMs

• For airlines: Ensures revenue integrity and compliance with fare rules.
• For travel agencies: Creates financial liability and extra administrative work. Many agencies invest in ADM prevention tools and ticket auditing software to reduce errors.

For travelers: Usually indirect but poor ADM management can increase agency costs, which may reflect in ticket pricing.