Hi all,

as a first time poster, hope this is the correct sub-forum to post this question in and I'd like in advance to thank the forum as it has been invaluably helpful over the years.

I am evaluating whether I should cancel a multi-city return flight from London to the USA (ie outbound LON-USA and return USA-LON - I can't state the destination city in the USA to maintain anonymity due to a delicate situation I am finding myself in). Both legs are in WTP bought fully cash (ie no rewards flight nor Avios & cash). Ticket non refundable (fare class T on both legs). Both legs operated by BA and booked through BA UK website (I am based in the UK).

When trying to cancel it, Manage my booking is not showing me the refunded tax amount. It's stating (as usual) that they will process the refund but I won't know in advance the amount. I have therefore called BA and the agent told me that I was due £232. This has been confirmed by calling different agents on different days, etc.

I understood that I would be entitled to a refund only of the tax portion less the £30 phone service fee (or £15 online fee if online). The issue I have is that, according to the ticket, the taxes are c. £300, less 30£ would be c. £270. Would you know by any chance the difference between my £270 calculation and the £232 quoted by the agent? The amount is minimal but I would like to understand the formula behind it (also for the future) and I'm sure I am missing something obvious. I attach the tax breakdown below for reference (this obviously doesn't include the YQ which I know is not refundable - all amounts in GBP):

Air Passenger Duty - United Kingdom £194.00 GB
Passenger Service Charge - United Kingdom £48.89 UB
Passenger Civil Aviation Security Service Fee - USA £4.40 AY
International Transportation Tax - USA £17.40 US
International Transportation Tax - USA £17.40 US
Animal & Plant Health User Fee (Aphis) - USA £3.00. XA
Immigration User Fee - USA £5.50 XY
Customs User Fee - USA £5.50 YC
Passenger Facility Charge £3.50 XF
Total government, authority and airport charges* £299.59

Thank you in advance for any help!