How Airline Travel Selling Works
What really happens when you book a flight? You search, compare, pay — and then your ticket arrives. But between clicking “Buy” and receiving your confirmation, a whole chain of systems works together to make your trip happen.
If you’ve ever booked a flight online and wondered what happens behind the scenes, you’re not alone. Most people never think about it — they just search, pick a flight, pay, and move on. But the journey your booking takes is surprisingly fascinating. It involves a system that was built decades before the internet existed, and that is now going through a massive transformation.
Let’s walk through the whole story, from start to finish, in plain language.
The old way — before the internet
Imagine it’s the 1970s. You want to fly from New York to London. You call a travel agency or walk into their office. The agent sits in front of a green computer screen that looks nothing like what we use today — it shows only text, no mouse, no graphics. The agent types cryptic codes to check which flights are available, what the price is, and whether there are seats left.
Behind that screen, the agent is connected to something called a Global Distribution System, or GDS for short. Think of a GDS as a giant, centralized marketplace that connects thousands of travel agencies with hundreds of airlines all around the world. The most well-known ones are Amadeus, Sabre, and Travelport — and they were all built between the 1960s and 1980s.
To this day, these systems still handle an enormous number of flight bookings worldwide. They work well, but they come from a time before personal computers, before the web, and before smartphones. Over the decades, airlines began to feel limited by them — like trying to sell a modern smartphone through a 1980s TV commercial.
The big change — what is NDC?
Around 2012, an organization called IATA (the International Air Transport Association, which represents most of the world’s airlines) introduced a new standard called New Distribution Capability, or NDC for short.
The idea is simple: instead of going through the old GDS systems, airlines can now communicate directly with travel sellers — online travel agencies like Expedia, Kayak, or corporate booking tools — using a modern, internet-friendly language. It’s like switching from sending telegrams to sending emails.
Why does this matter for you? Because NDC gives airlines the freedom to offer much more than just a seat and a price. They can show you exactly what’s included in each fare, offer personalized upgrades, bundle services like baggage and seat selection, and change prices dynamically based on demand — all in real time.
Before NDC, if an airline wanted to introduce a new product — say, extra-legroom seats or a fare with lounge access included — it was slow and complicated. With NDC, it’s much faster, and the information reaches you, the traveler, more accurately.
What happens when you book a flight — step by step
Let’s follow a real booking, step by step, from the moment you open a travel app to when you receive your e-ticket.
Step 1 — You search for a flight
You type your cities and dates, and hit search. Your travel app sends a request to the airline (or to an aggregator like Norba that connects to many airlines at once). The airline looks at its inventory and sends back a list of available flights, with prices, departure times, and fare conditions.
Depending on the airline, this can include details like how many bags are included, whether you can change the ticket, and what meal options are available. All of this happens in a second or two.
Step 2 — You pick a flight and see the final price
Once you select a flight, the system locks in the price and calculates the total with all taxes, fees, and any discounts. This is important because flight prices can change very quickly — by confirming your choice, you “reserve” that price for a short period.
Step 3 — You choose extras
Before paying, you can usually add extras: a checked bag, a seat with more legroom, priority boarding, travel insurance, a meal, or lounge access. The system asks the airline what’s available and how much each extra costs, and shows it to you in the app. You pick what you want.
Step 4 — You pay and the booking is created
This is the big moment. You enter your details (name, contact info, passengers), choose a payment method, and confirm. Behind the scenes, your travel app sends all this information to the airline: which flight you picked, who’s traveling, what extras you chose, and your payment.
The airline processes the payment, creates a reservation in its system (sometimes called a PNR — Passenger Name Record), and sends back a confirmation with a booking reference and ticket numbers. Your confirmation email arrives, and you breathe a sigh of relief.
Step 5 — You get your e-ticket
Shortly after booking, the airline issues an e-ticket. This is a digital document with a unique 13-digit number that represents the contract between you and the airline. It proves that you have a right to travel on those specific flights. Each segment of your trip (each takeoff and landing) gets its own ticket coupon inside that e-ticket.
Step 6 — Changing or canceling your booking
Plans change. If you need to modify your booking — change a flight, add a bag after booking, or cancel — the system sends a new request to the airline. The airline checks the fare rules (is your ticket refundable? changeable?), applies any fees, and updates your reservation accordingly.
This is where things can get complicated depending on the fare you bought. A flexible ticket makes changes easy; a deeply discounted fare might not allow changes at all. The rules are set by the airline and are determined by the specific fare you purchased.
Who makes all of this work?
The whole process involves many players working together:
- The airlines — they have the planes, the seats, and set the prices and rules.
- Travel agencies and OTAs — companies like Expedia, Kayak, or your corporate travel desk. They provide the interface you use to search and book.
- GDS systems — the legacy middlemen that still connect many agencies to airlines.
- NDC aggregators like Norba — modern platforms that connect travel sellers directly to airlines through the NDC standard. Norba acts as a bridge: instead of a travel app having to build a separate connection to every single airline (each with its own rules, formats, and quirks), it connects once to Norba and gets access to dozens of airlines through a single, consistent system.
- Payment processors — they handle the actual money transfer securely.
What does this mean for you?
The shift from the old GDS world to NDC is changing how we buy flights. For travelers, it means:
- More choice. Airlines can display their full range of products, not just a basic seat.
- Better information. You’ll know exactly what’s included before you book — no surprises about bag fees or change policies at checkout.
- More personalized offers. Airlines can tailor prices and bundles based on your needs and loyalty status.
- Faster innovation. When airlines can introduce new products more easily, travelers benefit from new options and better experiences.
But the transition is not instant. Many airlines still use a mix of old and new systems. Some are fully modernized; others are still catching up. The result is a complex but fascinating ecosystem that, when it works well, makes booking a flight feel almost effortless.
Norba is the modern bridge between travel apps and airlines. We connect booking platforms to dozens of airlines through a single, simple interface — so you can search, book, and manage flights without the complexity. Learn more at norba.io.