This cropped upped up in the pub yesterday
Customer moaning about the fact that his tax had gone up after he changed job
MDTP - You should phone HMRC on this number and they'll sort it out
C Do I have to apply for a refund ?
MDTP - yes but I'll help you with it
C- Thanks would you like a beer ?
At this point the barmaid pointed me out to C and said ask him
Me - Did you get a P45 from your last employer
C - yes
Me - have you given it to your new employer
Me If you do that he'll adjust your tax
MDTP drank his free beer and left
No C didn't buy me beer but got the hump