by AvocadoK on Sun Jan 29, 2012 4:00 pm
It does seems as if the underpayment arises because of the second job.
Taking the NHS job first, you mention that you have gone into higher rate because you are working overtime. The PAYE system will take account of the extra earnings, and should collect the right amount of tax on that job. If the wrong amount was deducted, (which is unlikely), then the employer is to blame.
Taking the second job next, the way the system normally works is that the employer will deduct basic rate tax, with no allowances. In your case, basic rate tax was not enough, so not enough tax was deducted. An underpayment this arose.
The key question is, was that underpayment of tax due to HMRC's failure to deal with information it has received from you, or your employer to the extent that it affects your coding. The answer - within the terms of the concession - seems to be 'no', and that is why they will not refund the tax. This seems harsh, but as mullet says, it is a result of the way PAYE works, and because the old PAYE system was never really designed to cope with multiple jobs. Hopefully the shift to the new system will help avoid these situations happening so often.
You have my sympathy, and if I thought that HMRC was misapplying the concesssion, I would gladly help you. As it is, I think the adjudicator is the right road for you to go down.
Regards
AK