http://www.hmrc.gov.uk/incometax/codes-basics.htm
BR is the first listed in the other tax codes section and it states the following for the reason it's used.
Is used when all your income is taxed at the basic rate - currently 20 per cent (
most commonly used for a second job or pension)
The OP has two jobs and as such has to pay tax at the 20% rate.
[..]
No, he doesn't. "most commonly used" does not mean "always applies in all circumstances regardless of what the law says".
As I said before, the income tax system is set up with the assumption of a single source of income. By default, your personal tax allowance is applied to one income only. That is usually fine, but not always.
The OP is one person. So the OP has one personal tax allowance. It does not matter if they have one income, two incomes or a hundred incomes. They have one personal tax allowance. Because they're one person. Their total income is less than their personal tax allowance, so they are not liable for income tax. At all. They are being taxed solely because the system is not set up to correctly deal with one person having more than one income. They can fix the problem by contacting HMRC and having their personal tax allowance split between the two jobs.
OP, default position 1:
Filled out a P45 for the council job and a P46 for the Wetherspoons job.
Personal tax allowance is assigned to the council job.
OP is taxed at BR on the Wetherspoons job.
OP, default position 2:
Filled out a P45 for the Wetherspoons job and a P46 for the council job.
Personal tax allowance is assigned to the Wetherspoons job.
OP is taxed at BR on the council job.
OP, default position 3:
Forms not correctly used or lost in the system..basically anything other than correct P45/6 usage.
Tax system reverts to default and the OP is taxed at BR for everything.
OP fixes the problem temporarily:
OP contacts HMRC and says he's paying too much tax. They check, find that he is and give him a rebate. Works fine until the next tax year.
OP fixes he problem permanently:
OP contacts HMRC and asks them to split his personal tax allowance, with £2500 assigned to the Wetherspoons job and the remainder to the council job.
OP pays no income tax,
correctly so because his total taxable income is less than his personal tax allowance.