2 different tax codes in one year?

r0bb077

My mother has just had a letter from the tax office saying she's underpayed her tax from last year.

Unfortunate circumstances last year meant she had to go part-time at work, and her tax code changed from 412L to 362L for the last 3 months of the taxable year.

Is there anyway of working out yourself how much tax she should of actually paid if you have 2 different tax codes in 1 year??

CLAPTON

not many facts here
but assuming the second tax code was accumulative then the total tax for the whole year will be determined by the last taxcode

however if you wish to give details we could check it's correct

so how much did she earn
how much tax did she pay (should be on her P60)
any benefits in kind
any other sepcial circumstances

becoming parttime should make no difference to her taxcode