How airfare pricing actually works

Fares look arbitrary from the outside. They are not — they are the output of a fairly mechanical system that has been running largely unchanged for decades. Understanding four things about it will make almost every price you see on a search page explicable.

1. An aircraft is not one product, it is twenty

Airlines do not sell “an economy seat.” They sell a set of lettered fare buckets that all happen to sit in the economy cabin. A single 180-seat aircraft might have a dozen economy buckets on it, each with its own price, its own rules and its own allocation of seats.

The cheapest bucket sells out first. When it does, the next search returns the next bucket up, and the price appears to have “gone up” even though nothing about the flight changed. This is why refreshing a search sometimes shows a higher number and refreshing again shows the old one: you are seeing inventory move, not a website tracking you.

2. Advance purchase is a rule, not a trend

Most fares carry an advance purchase requirement — 21 days, 14, 7, 3. These are hard conditions written into the fare, not soft pricing behaviour. When you cross one, the cheaper fare stops being available to you entirely, which is the single biggest reason last-minute travel costs what it does.

This is also why generic “book on a Tuesday” advice does not survive contact with reality. What matters is which side of an advance purchase boundary your travel date sits on, and how much of the cheap bucket is left.

3. Fare brands sit on top of buckets

In the last decade airlines have layered marketing names on top of the bucket system: Basic, Standard, Flex, Plus, and so on. Two results in the same cabin at different prices are usually two different brands, and the difference is almost never legroom — it is the bundle:

• Seat selection. Free, paid, or not permitted until check-in.
• Cabin bag. Some basic fares in North America and Europe allow only a personal item.
• Checked bag. Included, or charged per bag per direction.
• Changes. Free, fee-plus-fare-difference, or forbidden.
• Boarding and upgrades. Lower priority and no upgrade eligibility on the cheapest brands.

Every result page here shows the filed brand under the price and the bag allowance on the card, because a $40 gap between two results usually turns out to be a $70 bag fee in disguise. Our baggage and seat guide goes through the bundles carrier by carrier.

4. The route, not the distance, sets the floor

Competition on a city pair matters far more than how far the aircraft flies. A 900-mile route with three carriers on it will often price below a 400-mile route with one. Hub-to-hub routes carry a premium because connecting passengers have no alternative. Routes that a low-cost carrier has recently entered collapse in price and stay collapsed until it leaves.

Things that genuinely move the number

Things that do not

Clearing cookies, browsing privately, using a VPN, or searching at 3am do not change the fare you are quoted. Airline inventory systems price on route, date, bucket availability and party size. They are not looking at your browser.