Fare basis code


A fare basis code is an alphabetic or alpha-numeric code used by airlines to identify a fare type and allow airline staff and travel agents to find the rules applicable to that fare. Although airlines now set their own fare basis codes, there are some patterns that have evolved over the years and may still be in use.
Fare codes start with a letter called a booking class which almost always matches the letter code that the reservation is booked in. Other letters or numbers may follow. Typically a fare basis will be 3 to 7 characters long, but can be up to 8.

Booking class

The first character of the fare basis code is always a letter, and will almost always match the booking class. Booking codes are the identifiers used by the airline's revenue management department to control how many seats can be sold at a particular fare level. For example, a plane may have 25 economy seats still available and the airline may show it in a reservation system as Y7 K5 M4 T6 E3 which indicates how many of each booking class can be reserved. Some codes cannot be sold by agents, and those seats may be reserved for international connections, loyalty programs, or airline staff relocation.
Booking codes were defined by IATA, but airlines have deviated from the IATA standard and current booking codes are airline-specific. The same code may have different meanings for tickets issued by different airlines. Many airlines use nearly all letters of the alphabet to allow finer yield management. Nevertheless, certain booking codes have retained the same meaning across most airlines:
Booking codeMeaning
Ffull-fare First class, on airlines which have first class distinct from business class.
Jfull-fare Business class
Wfull-fare Premium economy
Yfull-fare Economy class

Other common patterns

Letters and numbers in other sections of the fare basis code may provide the following information:
CodeStandard position in fare basis codeMeaning
ESecond letterThis often indicated that the fare was an "Excursion Fare". These fares typically had a minimum and maximum stay requirement to encourage use by the holiday market and not business travellers.
NumeralsLatter parts of the fare basisNumerals often indicate the maximum stay the fare rules will allow at a destination. Thus a YE45 is an economy excursion fare with a maximum stay of 45 days. Similar patterns could be YE3M indicating a 3-month maximum.
H or LOther than first letterHigh or low season
W or XOther than as the first letterThese two letters are commonly used in airfares to state if a fare is valid on a weekday or restricted to weekends. The specific days of a weekend may vary, and can include Friday travel.
OWOn higher level fares, normally follows the initial booking code.One-way fare only
RTOn higher level fares, normally follows the initial booking code.Return fare
Two-letter country codesUsually at the end of the code, except if followed by "CH" or "IN"Fare bases often end with two-letter country codes. This will be the case when an airline has an international fare in both directions. For example, a fare from Great Britain to Australia may be YE3MGB, and YE3MAU from Australia to Great Britain. This allows the fare to have similar rules, but may have some variations in change fees or to comply with local trade restrictions.
CHLast two charactersChild fare
INLast two charactersInfant fare

Airline-specific codes

There is an endless list of other codes on modern fares. These are not standardized in any way, and may often be for short-term use. The following are some examples:
Each published fare basis code corresponds to a fare, which applies to travelling between two cities on a certain airline, with certain restrictions.
These restrictions can include, but not limited to:
which is published in legalese such that it can be validated automatically by global distribution systems.

Fare construction

Fare construction refers to the application of fares which can cover the flights in the reservation, necessary to price the air ticket for issuance.
It is commonly presented as a single line with standardized codes which can be used for travel agents to price the ticket in global distribution systems. For example, a fare construction may say:
Fare construction is a complicated task because each fare comes with a lot of rules regarding the usage, however the rules are designed to be validatable by computers so the system can decide to accept or reject easily. Most commonly fare construction is done by a computer automatically, but it is not guaranteed that the lowest fares can be found. Due to the above reason, or in case when the automatically-generated fare has some restrictions which the traveller does not want, manual fare construction can also be done, which means finding the suitable fares manually and applying the fares to an itinerary in order to buy a ticket.

Multiple fare basis

It is common for a multi-sector air ticket to have more than one fare basis, particularly if it is for carriage on more than one airline, or different classes of travel are involved. The issuing airline may often have an interline agreement to allow other airlines on the ticket. One disadvantage of this system is that if any change is made, the most restrictive fare rule, and/or the highest change fee, may apply to the entire ticket, not just the portion being changed.

Global Distribution Systems

In a Global Distribution System, the fare basis will typically display as part of a fare display, and will not normally be shown in an availability display.
Some modern booking systems allow availability searches using parameters such as time of day and lowest fare, and may negate the need for an agent to firstly study the fare basis rules.

Tickets

The fare basis is normally shown on the air ticket. On older paper tickets, it was highlighted on the relevant coupon for that flight. On modern e-tickets, it is often printed under the flight details.