Identify the ancillary service to be sold (excess baggage, seat upgrade, lounge access, etc.) and confirm it is filed as an ATPCO Optional Service with the relevant RFIC and RFISC codes
In the GDS, associate the service to the passenger's PNR using the appropriate SSR or OSI element referencing the RFIC/RFISC and the applicable flight segments
Collect payment for the ancillary and issue an Electronic Miscellaneous Document (EMD) against the PNR; the EMD can be standalone (EMD-S) or associated to a ticket (EMD-A)
Record the EMD number in the booking record and ensure the EMD-A is properly linked to the parent ticket number if the service is flight-coupon-associated
At check-in or boarding, the airline's system reads the EMD coupon status; verify the coupon is in an 'open' status and has not been consumed by a prior check-in
Known gotchas
EMD-A (associated) and EMD-S (standalone) have different lifecycle rules — EMD-A coupons are voided if the associated ticket is voided, EMD-S coupons must be independently refunded or voided
RFIC/RFISC code combinations are airline-specific; using the wrong codes can cause the EMD to be rejected at the airport even if issuance succeeds in the GDS
GDS EMD issuance commands vary by system (Sabre, Amadeus, Travelport); there is no universal API — always use the target GDS's own documentation
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp