Apologies for 'waking up' a reasonably old thread..

Have also had some endless 'need to put you on hold while we calculate the surcharge, sir' calls and quite frankly find this a quite messy and inconsistent process.

Found some disturbing information while making a partial UUA yesterday, following another painfully long conversation with the call center. So - apparently, with a partial UUA, the difference in carrier surcharge is applied not just to the sector you are upgrading, but to the whole fare component..

For example: If your itinerary is SFO(Y)-NYC(T)-LON(T)-HKG vv and you try to UUA only for NYCLON to Club World, they will apply 'carrier surcharge' (or 'fuel' if you like) as if the whole trip SFO-NYC-LON-HKG was flown in Club World.

While most partial UUAs are likely to be made on the longer flight (for example MAN-LON-DFW, and LON-DFW is upgraded), it is unlikely to make any difference, or for the amount to be sufficiently high for anyone to question it. However, in this case the very high additional surcharge I was quoted really didn't make sense so I challenged the amount.

After much ado, I finally had a confirmation that additional YQ should only be charged for the upgraded sector, however 'there is a flaw in the system which applies the charge to the whole fare component and we had to calculate this manually'. So essentially, it seems to be entirely coincidental how they charge this - and inevitably, the difference between 'good and bad' call center agents will govern how correct these surcharges apply. I really had to argue to get them to look at this and finally accept they had misquoted the amount - this shouldn't be necessary.

Anybody else been quoted unreasonably high 'taxes and fees' with partial UUAs? KARFA - perhaps you've had similar experiences? You seem to have plentiful words of wisdom on UUAs!