Travel into and out of UK is notorious for all the surcharges that are imposed on airfares but this seems to me like a ridiculous double surcharge! I just booked a TATL trip for September with the following itinerary: UA: EWR -> LIS (stopover) -- W fare TP: LIS -> LHR (stopover) -- W fare UA: LHR -> IAD -> LGA -- V fare for which the airfare of US$729 jumped to US$1,433.60 after including taxes and other surcharges, the lion's share of which was imposed by UK. This is shown graphically below: For instance note that the UK Air Passenger Duty ($100.80) and Passenger Service Charge ($59.80) are about 8 times the fees imposed by Portugal and twice those imposed by US. On top of that one gets slapped with an International Surcharge of $458, all of which brought the various taxes and surcharges to about 50% of the cost of the ticket! Anyway, that was one of the better fares that I could find so I went ahead and purchased it. I wanted to request upgrades using GPUs but had to wait "because one or more flight segments associated with the confirmation shown above is on a codeshare partner(s). This itinerary will remain in effect for 24 hours through Sun., Jun. 2, 2013. Once our codeshare partner accepts this reservation your fare will be guaranteed, your ticket will be issued with the form of payment authorized and a receipt will be sent to you." [This is where UA frequently "forgets" to ticket reservations for award travel even after the partner had confirmed availability!] This morning, I got confirmation that the reservation had been ticketed. I logged into my account and sure enough all the links were active, so I requested upgrades for the UA segments using 2 GPUs. The U/G for EWR->LIS segment cleared right away, while the inbound int'l segment (LHR-IAD) has been waitlisted (IAD-LGA is a one-cabin flight). Then it was time to approve or cancel the upgrade request, and that is when I noticed it: in addition to the 2 GPUs, the upgrades would cost me US$100 for Airport Passenger Duty! This brings to mind a number of questions: How is this fee different from the UK Air Passenger Duty of $100.80 (see Fare Information Table) that I had already paid as part of the multiple surcharges for the ticket price?! Is UK/LHR double-dipping? Importantly, why is a request for a seat upgrade on a UA flight being charged an Airport Passenger Duty? Has it always been the case that GPUs for TATL flights are slapped with this fee? Inquiring minds wanna know because this fee on the GPUs seems ridiculous to me.