Status: checked against official sources; automated independent review
FREQUENT FLYER GLOSSARY
What is a fare basis code?
A fare basis code is an airline's identifier for the specific fare a ticket was sold under. It sits on the ticket next to the booking class — the single letter that places a reservation in a cabin's inventory, and the code programmes publish earning rates against. It is also the label the fare rules are written against. The distinction matters for earning, because programmes read the booking class, and sometimes the cabin and fare type, when they calculate miles and tier points: Singapore Airlines credits KrisFlyer miles at 200% of miles flown in Suites and First Class booking classes A and F, but at 100%, 75% or 50% in Economy Class depending on booking class. [4]
Facts checked: 18 October 2026
Key takeaways
- A fare basis code names one priced fare and carries that fare's rules; the booking class is the one-letter code printed alongside it.
- Mileage programmes usually key earning to the booking class. KrisFlyer sets different accrual percentages for different Singapore Airlines booking classes within the same cabin. [4]
- British Airways uses cabin, booking class and a percentage of miles flown for several partner airlines [3], and from 1 April 2026 adds extra tier points based on fare type, with Basic Economy fares excluded. [3]
- Award and redemption tickets fall outside normal earning: British Airways awards no tier points on Reward Flights [3], and Singapore Airlines awards no KrisFlyer miles, Elite miles or PPS Value on award tickets. [4]
What is the difference between a fare basis code and a booking class?
A booking class is a single letter. British Airways publishes tier-point tables for its partner airlines as lists of cabin groups and single-letter booking classes [3], and Singapore Airlines publishes its KrisFlyer accrual chart the same way, with booking class letters grouped under Suites/First, Business, Premium Economy and Economy. [4] A fare basis code is longer and more specific: it identifies the actual fare that was priced, including the fare type, and the fare rules are written against that fare.
Because earning can turn on more than the letter, two passengers in the same cabin on the same flight may earn different amounts. British Airways awards different numbers of extra tier points for Plus, Semi-Flex and Fully-Flex fares within the same cabin [3], and Singapore Airlines pays 150% of miles flown in Business Class booking classes Z, C and J but 125% in D and U. [4] The two codes are therefore related but not interchangeable, and the booking classes and fare brands explainer shows how airlines group them into selling families.
How does booking class affect mileage earning?
Booking class is the most common input to mileage earning. Singapore Airlines publishes KrisFlyer accrual as a percentage of actual miles travelled, set by cabin and booking class, and says members can earn KrisFlyer miles on most booking classes on its flights. [4]
| Cabin | Booking classes | Accrual level (of actual miles travelled) |
|---|---|---|
| Suites / First Class | A, F | 200% |
| Business Class | Z, C, J | 150% |
| Business Class | D, U | 125% |
| Premium Economy Class | S, T | 125% |
| Premium Economy Class | R, L, P | 100% |
| Economy Class | B, E, Y, M, H, W and Q, N, V, K, G | 100%, 75% or 50%, depending on booking class |
In practice the letter can change an economy ticket's earning several-fold: the same distance flown in a different Singapore Airlines economy booking class returns 100%, 75% or 50% of the miles travelled. [4] Where a ticket is upgraded to a higher cabin, Singapore Airlines says accrual of KrisFlyer miles and status credits (Elite miles and PPS Value) is based on the booking class fare or value of the original ticket before the upgrade. [4]
Programmes also use booking classes to grade partner flights. British Airways says that for some partner airlines tier points are calculated from cabin, booking class and a percentage of miles flown, and the letters differ from one partner airline to the next. [3] On Cathay Pacific flights, for example, British Airways lists Economy Lowest booking classes K, L, M, N, Q, S, V at 2% of miles flown and Economy Flexible Y, B, H at 7.5%, from 1 April 2025. [3] It also notes for several partners that discount economy flights may earn fewer tier points depending on the fare purchased. [3] For more on how the letter translates into a rate, see booking class earning and earning rate.
How do fare types affect British Airways tier points?
British Airways prices its own tickets in fare types that carry their own earning power. From 1 April 2026, members of The British Airways Club earn extra tier points based on the cabin and the fare type booked, and Basic Economy fares are excluded; extra tier points are awarded per individual flight. [3]
| Fare type | Euro Traveller, short haul | World Traveller, long haul |
|---|---|---|
| Plus (short haul) / Standard (long haul) | 75 | 150 |
| Semi-Flex | 175 | 250 |
| Flex | — | 350 |
| Fully-Flex | 275 | 450 |
The base calculation is separate and spend-based: 1 tier point for every GBP 1 of eligible spend on British Airways flights, where eligible spend means the fare plus any carrier-imposed charges, excluding non-airline taxes and fees such as airport charges and government taxes. [3] Members can see the tier points a booking will earn, including extra tier points, in the Review and Pay step of the booking flow and in Manage My Booking afterwards. [3]
Exceptions and limits
- Tickets that do not earn. British Airways says members do not earn tier points on Reward Flights. [3] Singapore Airlines says members do not earn KrisFlyer miles, Elite miles or PPS Value when they redeem for an award ticket, and do not earn them on the upgraded cabin class of a redemption upgrade, but continue to earn KrisFlyer miles on the original booking class. [4]
- Redemption upgrades. On Singapore Airlines, a member who upgrades with miles continues to earn KrisFlyer miles on the original booking class. [4]
- Negotiated and agency fares. For negotiated fares on British Airways-marketed flights booked through travel management companies in the UK, tier points are based on the equivalent fare available on ba.com at the time the booking was made; for other travel agency or travel management company bookings where the fare is not available or has not been disclosed, tier points are based on cabin, booking class and a percentage of miles flown. [3]
- Status bonuses sit on top. American Airlines says AAdvantage status members earn more miles and Loyalty Points when they travel with American, oneworld and partner airlines, and that bonus miles bought through its Mileage Multiplier offer do not count toward elite status qualification or Million Miler status. [1] Booking classes that earn nothing at all in a given programme are covered under ineligible fare classes.
Frequently asked questions
Is a fare basis code the same as a booking class?
No. The booking class is the single-letter code that programmes publish earning rates against, while the fare basis code identifies the specific fare that was priced. Singapore Airlines, for example, publishes KrisFlyer accrual by cabin and booking class. [4]
Do two tickets in the same cabin always earn the same miles?
No. Booking class splits one cabin into several earning levels: KrisFlyer pays 150% of miles flown in Business Class booking classes Z, C and J but 125% in D and U [4], and British Airways awards different extra tier points by fare type within the same cabin from 1 April 2026. [3]
Do award tickets earn miles or tier points?
In the programmes described here, no. British Airways awards no tier points on Reward Flights [3], and Singapore Airlines awards no KrisFlyer miles, Elite miles or PPS Value on award tickets, and none on the upgraded cabin class of a redemption upgrade, though KrisFlyer miles continue to be earned on the original booking class. [4]
What happens to my earning if I upgrade my ticket?
On Singapore Airlines, accrual follows the booking class fare or value of the original ticket before the upgrade, and a redemption upgrade continues to earn on the original booking class. [4]
Where can I see the booking class and expected earning before I book?
British Airways displays estimated tier points, including extra tier points, in the Review and Pay step and in Manage My Booking [3]; Singapore Airlines points members to its Miles Calculator and accrual chart for its own and partner flights. [4]
Sources
Sources accessed on 18 October 2026. Other programmes, including Delta SkyMiles, United MileagePlus, Flying Blue, Emirates Skywards and Miles & More, are not covered here.
- American Airlines: Earn on American Airlines, AAdvantage program, checked 18 October 2026
- The British Airways Club: Earning tier points on flights, checked 18 October 2026
- Singapore Airlines: Earning and redeeming KrisFlyer miles, checked 18 October 2026