<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by ebell:
US doesn't, but it comes pretty close. You can upgrade everything but its "e-saver" fares, which are the last-minute savings to special destinations. I recently travelled DCA-PHL-MAD roundtrip on a $340 (tax included) ticket and upgraded it just fine.</font>
Be careful. US does
not offer mileage upgrades for discount transatlantic fares. The lowest transatlantic upgradeable (with miles) fare is B-class and they usually run $1,200 or more per roundtrip. And those fares will still cost you 20k each way to upgrade. Full fare coach ($2,000+) and full fare business class fares can be upgraded for 10k each way.
As far as transatlantic coupon upgrading, US's elites (all three levels) are given 2 one-way confirmable in advance systemwide upgrade coupons. Top tier members get 2 additional for companion travel. These are good with
any purchased fare except for the internet e-saver fares. There are some recent rumors on the US board that not all elites (those who qualified for the lowest level, under reduced miles/segment requirements) will get these systemwide coupons next year.