I guess its just the timing, I just happened to look at the time it was there, presumably if I had looked in a day or two's it wouldn't even have been there so I would not have noticed it, but for sake of argument what would have happened if my overall limit was £2,000 or even £2,900? Presumably something would have bounced? Maybe my tickets ?

Does BA's method not mean you can only buy tickets worth half your credit card limit minus any existing spend?

Des anyone know why they do it this way? Is it common in the airline industry?