Airline ticketing and GDS

In short

Airline ticketing is the process of reserving a seat, constructing and quoting a fare, collecting taxes and surcharges, issuing an electronic ticket and later handling changes, refunds and no-shows. A Global Distribution System (GDS) is the neutral computer network — Amadeus, Sabre and Travelport (Galileo/Worldspan) — that connects a travel agent's terminal to hundreds of airline inventory systems so availability, fares and ticketing happen in one place. The topic matters because fare rules and ticketing discipline decide whether an agency makes or loses money on a booking, and an incorrectly issued ticket becomes an Agency Debit Memo. It is examined in BTTM/BBA (Travel & Tourism) "Travel Trade" and "Air Transport & Ticketing" papers, in IATA-UFTAA/IATA Foundation and Amadeus/Galileo certification tests, and in placement rounds for Thomas Cook, SOTC, MakeMyTrip, Yatra, EaseMyTrip, Cleartrip, TBO, Riya, Akbar Travels, Indigo/Air India ground and reservations roles, and travel BPOs (Accenture, WNS, Concentrix, Infosys BPM).

Explained

Codes, conventions and the vocabulary of ticketing

• IATA 3-letter city/airport codes: DEL (Delhi), BOM (Mumbai), BLR, MAA, CCU, HYD, COK, GOI/GOX, LHR, DXB, SIN, JFK. Multi-airport cities have a city code plus airport codes — e.g. city LON vs LHR/LGW/STN; NYC vs JFK/EWR/LGA.
• ICAO 4-letter codes are used by pilots and ATC (VIDP for Delhi, VABB for Mumbai), not by ticketing.
• Airline designators: IATA 2-character (AI Air India, 6E IndiGo, UK Vistara — now merged into Air India; QP Akasa Air, IX Air India Express, SG SpiceJet) and ICAO 3-letter (AIC, IGO).
• Airline accounting/numeric code — the 3-digit prefix of the ticket number (098 Air India, 312 IndiGo, 125 British Airways). A 13-digit e-ticket number = 3-digit airline code + 1 form code + 9 serial digits.
• IATA traffic conferences: TC1 Americas, TC2 Europe/Africa/Middle East, TC3 Asia/Australasia. India is in TC3 — journeys are classified intra-TC3, TC3–TC2, etc., which drives mileage and fare construction rules.
• Journey types: OW (one way), RT (round trip, same fare both ways), CT (circle trip, returns to origin via different routing), OJ (open jaw — outbound and inbound points differ), RTW (round the world).
• Other terms: stopover (break of over 24 hours at an intermediate point, usually priced), transit/connection (under 24 hours, not priced), MCT (minimum connecting time), gateway, sector/leg, segment, coupon, conjunction ticket (more than 4 coupons → linked tickets).

What a GDS is and how it works

• A GDS is a neutral, multi-airline reservation and distribution platform: one display shows every participating carrier's availability, fare and schedule, and can issue the ticket and the accounting record.
• Origin: airline CRS (computer reservation systems) — Sabre grew from American Airlines, Apollo/Galileo from United, Amadeus from a European airline consortium, Abacus (Asia) later merged into Sabre. CRS became GDS when they opened to third-party agents.
• Participation levels: an airline may be *schedule only*, *availability (seat count)*, *direct access* (real-time look into airline inventory), or *full/last-seat availability with direct sell* — the deeper the level, the more reliable the status.
• Links: AVS (availability status messages), Teletype/EDIFACT messaging between GDS and airline host; messages such as SSIM for schedules (PNRGOV is the separate passenger-data feed to government authorities, not a schedule message), ATFQ/TST for fares, and BSPLINK for settlement.
• Main systems used in India: Amadeus (largest market share), Galileo/Travelport, Sabre; plus InterGlobe Technology Quotient (Travelport's India distributor) and consolidators' own portals (TBO, Riya, Akbar, Via).
• Revenue model: the airline pays the GDS a segment booking fee per sector; the GDS may pay the agent a productivity/incentive share. Low-cost carriers avoided GDS fees by selling direct — hence India's heavy use of aggregator APIs for 6E/SG.
• NDC (New Distribution Capability) — IATA's XML standard letting airlines push rich content (bags, seats, bundles) straight to agents, bypassing classic EDIFACT GDS pricing; adoption is rising and GDSs now resell NDC offers. Treat market-share and surcharge details as fast-changing.

Classes, RBDs and fare basis

• Cabins: First (F/P/A), Business (C/J/D/I/Z), Premium Economy (W/E/S on some carriers), Economy (Y and the rest).
• RBD (Reservation Booking Designator) is a single letter representing a *price bucket* inside a cabin, not the seat quality: Y is the full-fare economy reference; Q, L, V, T, S, N, E are progressively cheaper. Y9 M4 V0 L7 on an availability display = seats sellable per class (9 means 9 or more; 0 means closed, use waitlist).
• Fare basis code carries the rules, e.g. YOW, QAP14, VLXAP7IN — typically: RBD letter + ticket designator (AP = advance purchase, OW/RT, EE excursion, IT inclusive tour) + season/day code + days of advance purchase + market suffix.
• Common restrictions in the rule (Cat 1–35 in ATPCO structure): minimum/maximum stay, advance purchase, blackout dates, Saturday-night rule, change/cancel penalty (Cat 16), day/time (Cat 2), seasonality (Cat 3), stopovers (Cat 8), combinability (Cat 10), baggage (Cat 29); routing is held in a separate routing map, not a numbered category.
• Published vs negotiated: published (IATA/airline tariff, filed through ATPCO), private/negotiated fares (contract fares loaded for a specific agency — seen in GDS as a tour code / Cat 35), IT fares for packages, group fares (usually 10+ passengers, series booking), net/consolidator fares.
• Special fares in India: armed-forces, senior-citizen and student concessions on Air India; UDAN/RCS capped fares on subsidised regional routes; unaccompanied minor, medical and bereavement fares are airline-specific.

Building a PNR, ticketing and post-sale servicing

A PNR (Passenger Name Record) is the booking file; its record locator is 6 alphanumeric characters. Mandatory elements, remembered as P-R-I-N-T:

1. P — Phone/contact (agency and passenger; AP field).
2. R — Received from (who requested — RF field; closes the entry).
3. I — Itinerary (segments, sold from availability or direct/long sell).
4. N — Name (exactly as in passport; title, no nickname; infant attached to adult).
5. T — Ticketing arrangement (TK/TL field — ticketing time limit or "ticketed" status).
6. Optional/service elements: SSR (Special Service Request — structured, 4-letter codes to the airline: WCHR/WCHS/WCHC wheelchair, VGML/AVML/HNML/CHML meals, INFT infant, UMNR unaccompanied minor, FQTV frequent flyer, DOCS passport data, SEAT/NSST), OSI (Other Service Information — free text, no action needed), remarks (RM/RI), ticket/fare elements (FA, FP form of payment, FV validating carrier, FT tour code).
7. Segment status codes: HK confirmed, HL waitlisted, HN holding need, UC unable/closed, UN unable (flight not operating), NO no action, TK/SC schedule change, RR reconfirmed, HX cancelled by airline.
8. Pricing and issue: quote with the fare-quote command → store the fare as a TST (Transitional Stored Ticket) in Amadeus (Galileo: filed fare) → issue the ETKT. Coupon status then runs O (open) → A (airport control) → U (used/flown) → E (exchanged) → R (refunded) → V (void).
9. Void vs refund: a ticket can be voided only on the day of issue within the BSP reporting period (same day, before the sales report closes) with no penalty; after that only a refund is possible, subject to the fare rule.
10. Exchange/reissue: compute the fare difference plus change penalty; the new ticket references the old in the FO (original issue) field; residual value may be held as an EMD (Electronic Miscellaneous Document; the old paper MCO/MPD is withdrawn).
11. Ancillaries (bags, seats, meals, lounge) are sold as EMD-A (associated) or EMD-S (standalone).
12. Documents: e-ticket itinerary-receipt, ETR/ERA display, baggage tag, boarding pass, FIM/involuntary reroute endorsements, ADM (Agency Debit Memo) / ACM (credit memo) raised by the airline for incorrect issuance.
13. DNB/no-show vs cancel: a cancellation before departure follows the penalty table; a no-show usually forfeits more and may void the return coupon unless the fare permits.

Fare construction, taxes and settlement

• Fare construction is done in NUC (Neutral Unit of Construction): local currency fare ÷ ROE (IATA Rate of Exchange) = NUC; NUCs are added along the journey and reconverted to the currency of commencement. ROE is published by IATA quarterly — use the current one, not a remembered figure.
• Checks on an international construction: MPM/TPM mileage check with EMS (5–25% excess mileage surcharge), HIP (higher intermediate point) check, CTM (circle trip minimum), BHC (backhaul check), and OJ/CT minimum checks. Most of this is done by the GDS auto-pricer; exams still ask the logic.
• Taxes and charges on an Indian ticket (YQ/YR are carrier-imposed, not taxes):
  • K3 = GST on air transport — 5% on economy and 12% on business/premium class (unchanged by the 2025 rate rationalisation, which set the general slabs at 5/18/40%).
  • IN = User Development Fee / Passenger Service Fee components, WO = ASF/airport charges, YQ fuel/carrier surcharge, YR carrier misc.
  • TCS: on an overseas tour programme package — 5% up to ₹10 lakh per buyer per financial year and 20% above ₹10 lakh (no nil slab); on other LRS remittances — nil up to the ₹10 lakh threshold, then 20% (5% for education/medical, nil for education funded by an approved loan) — administered under the current income-tax law; the Income-tax Act, 2025 replaced the 1961 Act from 1 April 2026 and renumbered all sections, so cite the provision by name (tax collection at source on overseas remittances/tour packages) unless the new section number is certain.
• Settlement: IATA BSP (Billing and Settlement Plan) in India — the accredited agent reports sales through BSPLink, gets a HOT/billing analysis, and settles on a fortnightly remittance calendar; ARC performs the same role in the USA. IATA accreditation needs a financial security/bank guarantee and an IATA numeric code.
• Commission in India: airlines moved to zero base commission; agency earnings now come from PLB (productivity-linked bonus), net/negotiated fares, GDS incentives and a service/management fee charged to the client (itself subject to 18% GST as a service).
• Regulatory frame: the Bharatiya Vayuyan Adhiniyam 2024 (in force from 1 January 2025, replacing the Aircraft Act 1934) with the Aircraft Rules 1937, DGCA CAR Series M (Part II on refunds and the 24-hour free lock-in/cancellation window, Part IV on denied boarding, cancellation and delay compensation), Carriage by Air Act 1972 (Warsaw/Montreal liability limits for baggage, delay and death), and the Consumer Protection Act 2019 for service complaints. Compensation amounts are revised by DGCA from time to time — verify current figures.

Working the GDS: command logic (Amadeus / Galileo)

• Command syntax differs by version and office profile; learn the logic (encode → availability → sell → name → contact → TL → end → price → ticket), not the keystrokes alone.

Entry : AN15NOVDELBOM/AAI
Reply : 1  AI 806  DEL 1 BOM 2  0730 0950  J4 C2 D0 Y9 M9 V4 T0  E0/320
        2  AI 866  DEL 3 BOM 2  1100 1315  J2 C0 D0 Y9 M7 V0 L0  E0/32N
Read  : flight 806, Terminal 1 to Terminal 2, J (business) 4 seats, D closed,
        Y 9+, T closed; E0 = e-ticket only; equipment A320.

Key points

• GDS - neutral network (Amadeus, Sabre, Travelport) giving agents one screen for multi-airline availability, fares, ticketing and settlement.
• CRS vs GDS - a CRS is one airline's inventory system; a GDS aggregates many CRSs for third-party sellers.
• PNR - the booking record; 6-character locator; mandatory elements P-R-I-N-T (phone, received-from, itinerary, name, ticketing).
• RBD - single-letter booking class = price bucket inside a cabin; Y is full-fare economy, lower letters are cheaper and more restricted.
• Fare basis - code that points to the rule set (advance purchase, min/max stay, penalties, routing, combinability).
• E-ticket number - 13 digits: 3-digit airline accounting code + form code + 9 serial digits; over 4 coupons needs a conjunction ticket.
• Coupon status - O open, A airport control, U used, E exchanged, R refunded, V void.
• Void window - same-day-of-issue, within the BSP reporting period, penalty-free; later it must be a refund.
• Stopover vs transit - over 24 hours at an intermediate point is a stopover (priced); under 24 hours is a transit.
• NUC and ROE - international fares are summed in Neutral Units of Construction converted at the IATA Rate of Exchange, then reconverted to the currency of commencement.
• Mileage checks - TPM vs MPM with EMS 5/10/15/20/25%, plus HIP, CTM and backhaul checks.
• SSR vs OSI - SSR is a coded request needing airline action; OSI is informational free text.
• BSP/BSPLink - IATA's fortnightly settlement between accredited agents and airlines in India; ARC does this in the USA.
• ADM - Agency Debit Memo recovering an airline's loss from wrong fare, class, tax or unreported sale — the main commercial risk of careless ticketing.
• Zero commission - Indian carriers pay no base commission; agency margin = PLB + net fares + GDS incentive + service fee (18% GST on the fee).
• K3 - GST on the ticket: 5% economy, 12% business/premium; YQ/YR are carrier surcharges, not government taxes.
• DGCA CAR Series M - governs refunds, the 24-hour lock-in/cancellation window, denied boarding and delay/cancellation compensation.
• NDC - IATA XML standard for direct airline-to-agent rich offers, reducing dependence on classic GDS pricing.

Formulas and examples

Example 1 — Build the sell price of a domestic economy ticket (DEL–BOM, IndiGo) Base fare ₹4,200; YQ (fuel/carrier) ₹450; IN (PSF/UDF component) ₹240; WO ₹150; agency service fee ₹300.

1. Fare + YQ = 4,200 + 450 = ₹4,650.
2. K3 at 5% (economy) = 0.05 × 4,650 = ₹232.50 → ₹233 (rounded).
3. Statutory/airport charges = 240 + 150 = ₹390.
4. Ticket total = 4,650 + 233 + 390 = ₹5,273.
5. Service fee ₹300 + 18% GST on it (₹54) = ₹354.
6. Amount collected from client = 5,273 + 354 = ₹5,627.

Example 2 — Same sector in business class Base fare ₹16,000; YQ ₹700; IN + WO ₹390.

1. Fare + YQ = ₹16,700.
2. K3 at 12% = 0.12 × 16,700 = ₹2,004.
3. Ticket total = 16,700 + 2,004 + 390 = ₹19,094.
4. Note the K3 jump: the same sector pays 5% in economy and 12% in business — a classic exam trap.

Example 3 — Cancellation refund Round-trip ticket ₹11,800 total, of which base fare ₹8,000, YQ ₹1,200, taxes (K3 ₹460 + IN/WO ₹2,140) ₹2,600. Fare rule: cancellation penalty ₹3,500 per sector pair; agency charges ₹250 handling.

1. Refundable: base + YQ are subject to penalty; statutory airport taxes (IN/WO) are refundable even on a non-refundable fare, and K3 follows the refunded fare.
2. Fare component available = 8,000 + 1,200 = ₹9,200; less penalty ₹3,500 = ₹5,700.
3. K3 refunded proportionally = 5% of 5,700 = ₹285 (K3 collected ₹460 → ₹175 retained with the penalty portion).
4. Airport taxes refunded in full = ₹2,140.
5. Gross refund = 5,700 + 285 + 2,140 = ₹8,125; less agency handling ₹250 → ₹7,875 to the passenger.
6. Airline practice on exactly which components are retained varies by carrier and fare; always read the penalty table and the refund screen.

Example 4 — Reissue with date change Original DEL–BLR fare ₹3,600 + taxes ₹900 = ₹4,500. New date's lowest available fare in the same RBD family: ₹5,900 base. Change penalty ₹2,000; new taxes ₹1,050.

1. Fare difference = 5,900 − 3,600 = ₹2,300.
2. Tax difference = 1,050 − 900 = ₹150.
3. Collect = 2,300 + 2,000 + 150 = ₹4,450 (plus GST on the service fee if charged).
4. New ticket shows the old number in the FO field; old coupon status becomes E (exchanged).

Example 5 — Mileage / EMS check (international, logic) BOM–DXB–LHR. TPM BOM–DXB 1,200 mi + TPM DXB–LHR 3,414 mi = 4,614 mi. MPM BOM–LHR = 5,364 mi.

1. TPM total 4,614 ≤ MPM 5,364 → no excess mileage surcharge; the through fare applies (0M).
2. If the routing were BOM–SIN–LHR with TPM 2,432 + 6,764 = 9,196 mi against MPM 5,364: ratio = 9,196/5,364 = 1.714 → 71.4% excess, far beyond the 25% maximum, so the mileage principle fails and the fare must be built as separate components (or a different routing/fare used).
3. EMS steps: up to 5% → 5M, to 10% → 10M, to 15% → 15M, to 20% → 20M, to 25% → 25M; beyond 25%, construct a fare break.
4. Mileage figures above are illustrative; always read the current TPM/MPM from the GDS or IATA manual.

Where it is used

• Retail and corporate travel agencies: Thomas Cook, SOTC, FCM, American Express GBT, Balmer Lawrie, Riya, Akbar Travels — ticketing, reissues, ADM control, BSP reconciliation.
• OTAs and consolidators: MakeMyTrip, Yatra, EaseMyTrip, Cleartrip, TBO.com, Via — pricing engines, GDS/NDC and LCC API integration, fare-rule mapping.
• Airline reservations, revenue management and airport roles: Air India, IndiGo, Air India Express, Akasa — inventory and RBD management, DGCA CAR Series M refunds, denied-boarding handling.
• Travel BPO/KPO and shared services: WNS, Accenture, Concentrix, Infosys BPM run offshore ticketing, queue management, refund and ADM desks for global agencies.
• MICE, cargo and tour operations: group and series fares, IT fares for packages, EMD-based ancillary sales; airline cargo uses the parallel AWB/e-AWB system.
• Certifications that open these jobs: IATA Foundation in Travel & Tourism, IATA-UFTAA consultant diploma, Amadeus/Galileo/Sabre basic and fares-and-ticketing courses.

Interview questions

• Q: What is the difference between a CRS and a GDS? A: A CRS is a single airline's own inventory and reservation system; a GDS aggregates many CRSs into one neutral platform that third-party agents use to book, price and ticket across carriers.
• Q: List the mandatory elements of a PNR. A: Phone/contact, Received-from, Itinerary, Name and Ticketing arrangement — the P-R-I-N-T elements; a PNR will not end-transact without them.
• Q: What does a booking class letter actually tell you? A: It is an RBD — a price and inventory bucket within a cabin, not a seat type; Y is full-fare economy and letters like V, T or L are cheaper, more restricted economy buckets.
• Q: Difference between SSR and OSI? A: SSR is a coded special service request the airline must act on (VGML, WCHR, UMNR); OSI is free-text information for the airline with no action required.
• Q: When can a ticket be voided rather than refunded? A: Only on the date of issue, within the same BSP sales-reporting period and before the coupon is used — after that, the fare rule's refund and penalty terms apply.
• Q: What is an ADM and how do you avoid one? A: An Agency Debit Memo is the airline's claim against an agent for a wrong fare, class, tax, commission or unreported sale; avoid it by pricing with the GDS auto-pricer, honouring fare rules and ticketing time limits, and keeping the audit trail.
• Q: What are NUC and ROE used for? A: International fares are converted into Neutral Units of Construction using IATA's Rate of Exchange so components in different currencies can be added, then the total is reconverted into the currency of commencement.
• Q: A passenger wants a 20-hour layover in Dubai priced as a free connection — possible? A: Under 24 hours is normally a transit, so it may stay a connection, but the fare's routing and stopover rules and the airline's own definition decide it — check the rule and whether a transit visa is needed.
• Q: Explain stopover versus open jaw. A: A stopover is a deliberate break of more than 24 hours at an intermediate point; an open jaw is a journey whose outbound destination and inbound origin (or the origin and final return point) are different cities.
• Q: How does a travel agency earn money if airlines pay zero commission? A: Through productivity-linked bonuses and negotiated net fares, GDS segment incentives, ancillary and insurance sales, and an explicit service/management fee charged to the client with 18% GST.
• Q: What GST applies to an air ticket in India? A: K3 on the ticket is 5% for economy and 12% for business/premium class on the fare plus carrier surcharge; the agency's own service fee attracts 18%.
• Q: How do you handle a schedule change that leaves a 25-minute connection? A: The segment shows a TK/SC status — check the MCT, rebook the passenger onto a legal connection in the same RBD or get the airline's waiver, reissue without penalty under the involuntary-change rule and reconfirm the SSRs.
• Q: What is NDC and why does it worry traditional agents? A: It is IATA's XML standard that lets airlines distribute dynamic, bundled offers directly, so content and the best prices may sit outside classic GDS pricing unless the agency adopts NDC connectivity.

Common mistakes

• Writing the name differently from the passport, or a surname/given-name swap — leads to denied boarding and a chargeable name-correction or a fresh ticket.
• Treating the RBD letter as the cabin: booking "Y" thinking it is the cheapest economy, or assuming J and C are different cabins.
• Ignoring the ticketing time limit (TKTL) so the airline auto-cancels the segments, then reselling at a higher fare.
• Confusing YQ/YR (carrier surcharges, retained by the airline) with statutory taxes, and so computing K3 or a refund on the wrong base.
• Applying 18% GST to an economy ticket — air transport is 5% economy / 12% business; 18% applies to the agency's service fee.
• Forgetting that statutory airport charges (IN/WO/UDF-PSF) are generally refundable even on a "non-refundable" fare, and so quoting a nil refund.
• Mixing up MPM with TPM, or adding fares in local currency instead of converting to NUC, in international fare construction.
• Memorising Amadeus and Galileo commands interchangeably — the logic is common but the syntax is not.

Related topics

Travel agency and tour operations · Itinerary planning and tour costing · Travel documents: passport, visa and insurance · Air transport geography and IATA regulations · Airport operations and ground handling · Revenue management and airline pricing