I must admit 50 kg for F is a bit low. As I'm used to 128 kg (32x4, including an extra one for BA Gold on JL and BA for instance), 50 kg feels very, very tight. It basically means that if I am going to carry a lot of luggage, I'll be avoiding SQ until I get PPS Club (100 kg is OK, even 70 kg as Star Gold may not be sufficient but i won't always know at the time of booking, so it means I'll have to be a bit conservative with my estimate). I can't be doing with paying USD 3,000 to carry 50 kg extra.
I totally accept it because I'm the one who was over the weight limit but it sort of left a somewhat bitter taste in my mouth to be charged USD 300 for 5 kg for being 5 kg over when flying paid F. Leaving a small amount of margin deliberately to "appear generous" by setting the limit at 45 kg and letting you check 10% extra for 'free' when their target is actually 50 kg could well be perceived better - only psychology but much of customer services is actually psychology, yes?
I really should have actually posted the excess though - it'd have been 1/5 of what I paid in excess baggage fees.
Anyway, warning to anyone flying ex-NRT! They are tight with excess baggage. If you get caught out, go to the post office - there is one at T1 open until 8 pm every day of the week.
(BA would even have gone as far to proactively suggest transferring some contents to hand luggage to avoid the excess baggage charge upon realising the overweight bags but none of that was forthcoming either - I guess there may have been an assumption that I didn't care about the money given the amount I spent on the ticket but...

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