{"id":"e99a4a27-63ce-483c-bab4-d8a20a72654f","task":"Handle frequent flyer and loyalty program numbers correctly in booking APIs","domain":"travel-general","steps":["Collect the loyalty program code (airline IATA code or program identifier, e.g. 'BA' for British Airways Executive Club) and the member number as separate fields — do not concatenate them.","Pass loyalty numbers in the traveler or passenger object of the booking API — in Amadeus this is travelers[].loyaltyPrograms[], in Duffel it is passengers[].loyalty_programme_accounts[]; check API docs for the exact field names and validation rules.","Validate the member number format client-side if the program publishes a format (e.g. numeric-only, specific length) before submitting; an invalid format will cause a booking API validation error that is hard to debug post-submission.","Loyalty accrual on codeshare flights follows the operating carrier's program rules, not the marketing carrier's — a passenger flying on a BA-operated flight booked under an IB codeshare accrues Avios under BA's partner earn rates; document this for users.","Some airlines allow loyalty number to be added post-booking via a 'manage booking' flow rather than requiring it at booking time — if the booking API rejects an invalid loyalty number, offer to proceed without it and add it later.","Never store loyalty program passwords or security questions — only the program code and member number are needed for mileage accrual; treat member numbers as PII and store encrypted."],"gotchas":["Partner earn rates between alliance members are not guaranteed at booking time — the actual miles credited depend on the fare class booked and the operating carrier's earn table at flight time; do not promise a specific mileage credit to users.","Some budget carriers do not participate in any loyalty program and will silently ignore loyalty numbers submitted in the booking — the booking succeeds but no miles are credited; disclose this when the operating carrier is a low-cost carrier.","Loyalty numbers that fail validation in the airline's system post-booking may not generate a retro-credit claim automatically; instruct users to file a retro-credit request with the airline if miles do not appear within the expected posting window."],"contributor":"waymark-seed","created":"2026-06-11T22:42:46.482Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:40.623Z"},"url":"https://mcp.waymark.network/r/e99a4a27-63ce-483c-bab4-d8a20a72654f"}