Apologies if this has been discussed before. I'm not yet adept with the search tool.

Last night I attempted to upgrade using an E-VIP from LHR to JFK and was told I'd have to pay an extra 20 pounds, or nearly $40, to do so. The agent said that the gov levies an extra 20 pounds on business class seats. I've never had to pay this when I upgraded before leaving the US; do AA agents in the US simply not know about this and therefore do not charge it?

Especially strange: I had been on the waitlist for the upgrade, and I had placed myself on the waitlist before leaving the US. The check-in agent informed me that even in order to remain on the waitlist I would have to pay the tax. And should the upgrade not clear, I could request a refund using the receipt he would give me. I asked him why I was not charged to put myself on the waitlist in the first place by US based AA Agents, and he replied that perhaps they don't know about the tax, as I suspected. Suspicious of all of this, I decided to re-address the questions I had with the attendants in the Flagship club. They confirmed everything the gate agent told me, though they strangely had no idea where I should send the request for a refund should the upgrade not clear. They also opined that the computer would not allow US based agents to upgrade a coach ticket out of London without acknowledgment of payment of the tax. I don't know about that. In any case, I took my name off the waitlist and flew coach.

But is this common knowledge? I guess the best informed upgrade before leaving the US.