United Airlines  
Fare Domestic International
Description
  
A First Class NA Discounted Fare First Class. Round The World First is booked in this class.
 
B Yes Yes Almost Full Fare Economy with minimal restrictions - also used Star * RTW
C Yes Business Fare Full Fare Unrestricted Business Class. Upgradeable to F domestically.
D Yes  Business Fare Discounted Business fare- used also on all "Business" Class Star RTW fares. Upgradeable to F domestically.
E Yes  No 'Ted' and some low web/discount fares from early 2005. Now officially elevated to above H class!
F First Class First Class Full Fare Unrestricted First Class
G Yes  No Travel Industry Economy Class fares
H Yes Yes Higher level Economy Class with few restrictions. Some "RTW" coach is H. May require twice the points to upgrade than Y or B fares.
I NA Business Upgrade Business Class Upgrade class from Economy (Better known as 'NC' class)
K Yes No Seasonal Economy Promotional Fares/Reduced Fare Gov’t contract etc
L Yes No  Discount Fare Economy with a lot of restrictions
M Yes Yes  Almost Full Fare Economy with few restrictions. May require twice the points to upgrade than Y or B fares.
N Yes No  Economy Class AWARD TICKET (Better known as 'XY' class)
O NA  Biz Award Business Class AWARD TICKET (Better known as 'XC' class)
P First Class NA Premium USA Transcon First Class on 3 classers
Q Yes Maybe** Discount Economy with moderate restrictions. (Bereavement tix are in Q)** Q can be a QUP that books into domestic F without the use of an upgrade instrument. Some Q fares are refundable.
R FC Award NA  First Class AWARD TICKET (Better known as 'XF' class)
S Yes No  Real Lowball coach with lot of restrictions. Reports that some are not mile earning ex UK/Brazil etc.
T Yes No  Heavy discount Fare Economy - often with a lot of restrictions
U Yes No  Showed up Nov/03 as booking class for "TED" also in mid 2005 a high level mainline class!
V Yes Maybe** Discount Fare Economy often with a lot of restrictions**
W Yes Maybe** Discount Fare Economy often with many restrictions**
X NA FC Upgrade First Class UPGRADE AWARD from paid Business* (Better known as 'NF')
Y Yes Yes  Full Fare unrestricted Economy class
Z NA Business Fare Heavily discounted Business Class - CANNOT (officially) be upgraded using either miles or SWU's or Sales Dept upgrade certificates.
 

Code Description
X Coach
X First / Business Elite
Yes Fare is Upgradeable
No Fare is NOT Upgradeable
NA Not Applicable
? Maybe

*Applies to THREE class equipment. In TWO class equipment, upgrading from coach to First is also in "NF" class. Two class aircraft [at present!] only run on North American routes. "Two class upgrades" are officially not allowed for paying pax - i.e. nothing one can do - whether with miles, and/or coupons of any kind will "officially" take you from paid coach to First on a THREE class aircraft.

**The ONLY official way to upgrade a "published" lower priced international Q, V, W, coach fare is with a SWU or certain Sales Dept or one-segment certs etc. (However as a "lottery" side bar to this, in 2006 United actively started offering PAID upgrades at check-in for many long haul International flights - $US550 one way being a typical price point.)

United Airlines, Inc. Updated: March 8 2006

FARES ARE PUBLISHED IN THE FOLLOWING DESCENDING CLASS OF SERVICE/BOOKING CODE ORDER:

1) FIRST CLASS:
BOOKING CODE: F

2) RESTRICTED FIRST CLASS:
BOOKING CODE: P
BOOKING CODE: A

3) BUSINESS CLASS:
BOOKING CODE: C

4) RESTRICTED BUSINESS CLASS:
BOOKING CODE: D
BOOKING CODE: Z

5) COACH CLASS:
BOOKING CODE: Y

6) RESTRICTED COACH CLASS:
BOOKING CODE: B
BOOKING CODE: M
BOOKING CODE: E
BOOKING CODE: U
BOOKING CODE: H
BOOKING CODE: Q
BOOKING CODE: V
BOOKING CODE: W
BOOKING CODE: S
BOOKING CODE: T
BOOKING CODE: K
BOOKING CODE: L
BOOKING CODE: G