Fare Classes Explained: How the Letter on Your Ticket Sets the Price

A fare class is the one-letter code an airline puts on your ticket to mark the price level you bought inside a cabin. Two passengers in the same row can hold different letters, pay different fares and earn different miles. Here is what the letters mean at Delta, Singapore Airlines and Cathay Pacific, how to read a fare basis code, and when the letter matters while you book.

What is a fare class?

A fare class is the letter an airline assigns to your ticket to mark which of its prices you paid. Cathay Pacific spells out what rides on it: your checked bag allowance, whether you can pick a seat in advance, how many miles and status points you earn, and whether you can upgrade with miles. You will also see it called a booking class or booking code.

The fare class is not the cabin. US rules define class of service as seating in the same cabin, such as First, Business or Economy, or the same seating zone, such as Premium Economy. Inside one cabin an airline sells many fare classes at once, so the seat can be identical while the price and rules behind it are not.

Fare class vs cabin class vs fare basis code

One ticket carries 4 labels. Here they are for a Delta Main Basic fare, using Delta’s own published example:

Term	What it identifies	Delta example
Cabin (class of service)	Where you sit	Economy
Fare type or brand	The package of rules sold at checkout	Delta Main Basic
Fare class (booking class)	The price level, as one letter	E
Fare basis code	The exact fare and its rules, up to 8 characters	XEVQA0BA

Delta’s fare classes from highest to lowest

Airlines sell each cabin at several price levels at the same time, and each level gets its own letter. Delta’s SkyMiles exception fare chart lays out its ladder, from the full fares at the top of each cabin down to basic economy:

Letters	What Delta calls them	Miles on an exception fare
J	Delta One or First Class	150% of distance
C, D, I, Z	Discounted Delta One or First Class	150% of distance
P, A, G	Delta Premium Select	150% of distance
Y, B, M, W, S	Full-fare Delta Main or Delta Comfort	100% of distance
H, Q, K, L	Delta Main	75% of distance
U, T	Discounted Delta Main	50% of distance
X, V	Deeply discounted main cabin	50% of distance
E	Delta Main Basic	None

Exception fares are certain tickets sold through travel agents, consolidators, cruise lines and vacation packages, where the price often is not shown. On those, the letter sets your miles: a 1,000-mile trip in K earns 750 miles, and the same trip in V earns 500, before any Medallion bonus.

Tickets bought at a published price earn by the dollar instead. As of October 2026, Delta gives a general SkyMiles member 5 miles per $1 on Classic or Refundable fares, 7 on Extra and 2 on the Basic fares in its other cabins, counting the base fare and carrier surcharges but not government taxes. Delta Main Basic earns nothing either way, so of two people in the same Delta Main row, one holding an L and one an E, only the first earns miles.

Fare class letters are different at every airline

Each airline sets its own letters, so a fare class only means something next to the airline’s name. The same letter can sit near the top of one airline’s ladder and near the bottom of another’s.

Letter	Delta	Singapore Airlines	Cathay Pacific
Y	Full-fare Delta Main or Delta Comfort	Economy Flexi	Economy
B	Full-fare Delta Main or Delta Comfort	Economy Flexi	Economy
E	Delta Main Basic	Economy Flexi	Not an economy letter
S	Full-fare Delta Main or Delta Comfort	Premium Economy Flexi	Economy
K	Delta Main	Economy Lite	Economy
U	Discounted Delta Main	Business Standard	Not an economy letter
D	Discounted Delta One or First Class	Business Lite	Not an economy letter
A	Delta Premium Select	First or Suites	Not an economy letter

E is the starkest case. At Delta, E is Delta Main Basic, the airline’s basic economy fare, which earns no miles and cannot be upgraded. At Singapore Airlines, E is one of the 3 Economy Flexi letters, the most flexible economy fare it sells, with free changes and full KrisFlyer miles.

Even where the cabin matches, the rules do not. K is economy at all 3 airlines, but at Singapore it is Economy Lite, with no changes and half the miles of Flexi, while at Delta it is a Delta Main fare.

What your fare class decides: miles, upgrades, seats and changes

The fare type name you pick at checkout is the label; the letters are the codes underneath it. Singapore Airlines prints both on one page, with 2 or 3 booking classes under each economy fare type.

Fare type	Booking classes	KrisFlyer miles	Advance seat	Upgrade with miles	Change	Cancel
Lite	V, K	50%	Fee	Not allowed	Not allowed	Not allowed
Value	Q, N	50%	Free standard seat	Not allowed	Fee	Fee
Standard	M, H, W	75%	Free standard seat	Allowed	Fee	Fee
Flexi	Y, B, E	100%	Free standard or Forward Zone seat	Allowed	Free	Fee

At Singapore, checked bags do not change with the letter on US routes: every economy fare type gets 2 pieces of up to 23 kg on flights to and from the USA. Change and cancellation fees run lower on the higher fare types, and both Singapore and Cathay Pacific say the amounts can change without notice, so check the figure in your fare rules before you pay.

A Singapore ticket that mixes fare types across its flights follows 2 rules: the most restrictive cancellation fees apply to the booking, while change fees, seats, bags, miles and upgrades follow the fare type on each flight.

Cathay Pacific sells its 11 economy letters (Y, B, H, K, M, L, V, S, N, Q and O) as 3 fare types:

• Light: choosing a regular seat in advance costs a fee, changes cost a fee plus any fare difference, and you cannot upgrade with miles.
• Essential: free regular seats in advance, changes for a fee plus any fare difference, and eligible for upgrades with miles.
• Flex: free regular, preferred and extra legroom seats, free changes plus any fare difference, upgrades with miles and standby for an earlier flight.

All 3 charge a fee to cancel, and all 3 earn miles and status points at rates that vary by fare type and fare class.

How to read a fare basis code

A fare basis code is the longer code behind your fare class. It names the exact fare you bought, and the airline’s fare rules attach to it. Delta caps its codes at 8 characters and uses all 8 in most domestic and international markets. Fare search tools such as ITA Matrix let you search for a specific code.

The first letter is often the booking class, but not always. Delta books basic economy in E while the fare basis code may start with X, V or another letter, so confirm the booking class on your itinerary rather than reading it off the code.

Delta publishes the rest of its structure for travel agents, and these positions decode Delta fares only:

• 7th character (second from last): the product. On domestic fares, F is Delta First, D Delta One, Q, U, G or P Delta Premium Select, C or I Delta Comfort, M Delta Main and B Delta Main Basic.
• 4th character: on domestic fares, 1, 2, 3, 4, 5, H, P, R, X, Y or Z marks Delta’s Extra and refundable fares; international fares carry that marker in the 6th position.
• Full fares: codes such as Y0, Y9, Y9F, Y9D or a plain Y.

Delta last updated its agency fare basis page on 8 July 2026, the day new Basic fares such as Delta First Basic and Delta Premium Select Basic went on sale.

Example fares for illustration, October 2026: two travelers on the same domestic Delta flight, a row apart. The codes are Delta’s own published examples.

Detail	Traveler A	Traveler B
Fare paid (example)	$189	$139
Fare basis code	KA7UA0MC	XEVQA0BA
7th character	M: Delta Main	B: Delta Main Basic
4th character	U: no Extra or refundable marker	Q: no Extra or refundable marker
First letter	K, a Delta Main letter	X, though Delta books basic economy in E
SkyMiles for a general member	5 per $1 of base fare and carrier surcharges	None

• Same cabin, $50 apart: both sit in Delta Main, and the extra $50 buys a Delta Main fare that earns miles instead of a Delta Main Basic fare that earns none.
• Result: read the 7th character for the product and the 4th for the Extra or refundable marker, then confirm the booking class on the itinerary.

Does your fare class affect getting bumped?

It can, but only as one factor among several. When an oversold flight gets too few volunteers, each airline picks who is denied boarding by its own written priority rules, and federal rules let those rules count the fare you paid.

So a higher fare class is no guarantee, and how much the fare counts depends on the airline. Check-in time is on the same list, and checking in early is something you can do on any fare.

Fare classes on codeshare and partner flights

When you book a codeshare, the airline that sold you the ticket and the airline flying the plane can be different, and the perks of your fare type do not always cross over. Miles change too: Delta awards SkyMiles differently on partner flights than on its own.

How to find your fare class and use it when you book

Read the fare type before the letter. The fare type name at checkout tells you what you get for bags, seats, changes and refunds, and the letter matters after that for miles, upgrades and, at the margin, bumping priority.

Read the fare, then the letter

1. Pick the cabin, then compare the fare types the airline sells in it: Basic, Classic, Extra and Refundable at Delta, Lite to Flexi at Singapore Airlines, Light to Flex at Cathay Pacific.
2. Open the fare rules for the type you are leaning toward and check bags, seat selection, changes and cancellation before you pay.
3. Check who operates each flight, since a partner-operated flight can follow the partner’s conditions.
4. Look for the booking class letter for each flight on your e-ticket receipt, confirmation or the airline’s manage-booking page, and ask the agent if a travel agent booked it.
5. Match the letter against the airline’s own fare class chart if you want to upgrade with miles: Singapore Lite and Value and Cathay Light are not eligible.
6. Use the letter to estimate miles on a package or agency ticket: on a Delta exception fare, the letter sets the percentage of distance you earn.