What Splitting Your Allowance Actually Does
Under PAYE, HMRC normally gives your full Personal Allowance to one employer, usually your main job. Every other job then gets a code like BR (basic rate) or D0 (higher rate), meaning all earnings there are taxed from the first pound.
Splitting the allowance does not change how much income tax you owe for the year. Your tax bill is worked out on your total income across all jobs, with one £12,570 Personal Allowance and the same bands, however the allowance is spread between employers. What a split changes is how much is deducted from each payslip as you go, so that you are not overpaying all year and waiting for a refund, or underpaying and facing a bill later.
💡 Example: a café job paying £9,000 and a retail job paying £28,000. Combined income is £37,000, so the tax due for the year is 20% of (£37,000 minus £12,570) = £4,886, whichever job holds the allowance. The split only decides whether that £4,886 is collected evenly through the year or corrected afterwards.
When a Split Is Worth Asking For
- Your main job pays less than £12,570. Part of your allowance goes unused there while the second job is taxed at 20% from the first pound, so you overpay every month. Moving the unused allowance to the second job fixes that.
- Your pay in each job is predictable. HMRC bases the split on your expected earnings, so it works best when hours and pay are steady.
- Your combined income crosses £50,270. Here the issue is the opposite: a BR code on the second job may collect too little, because some of that income should be taxed at 40%. HMRC may give that job a D0 code instead so the right amount is collected during the year rather than as an underpayment later.
If your main job pays well above £12,570 and your combined income stays under £50,270, the standard setup (full allowance on the main job, BR on the second) already collects the right amount, and there is nothing to gain from a split.
How to Ask HMRC for a Split
- Make sure HMRC knows about both jobs. Check your employments in your Personal Tax Account or the HMRC app, or call the Income Tax helpline on 0300 200 3300.
- Ask for the allowance to be divided. Tell HMRC roughly what each job will pay over the year. They will work out the split and issue a tax code to each employer.
- Check the new codes on your payslips. A split shows up as two smaller codes, for example 1000L on one job and 257L on the other, which together add up to your full allowance.
- Review it if your hours change. If one job's pay rises or falls, the split can leave you over or under paying, so update HMRC when your pattern changes.
⚠️ A BR code on a second job is the normal, correct treatment for most people. Only ask for a split if your main job leaves part of your allowance unused.
Student Loans and Multiple Jobs
Splitting your allowance has no effect on student loan repayments. Each employer checks only its own pay against the repayment threshold for your plan, so with two jobs you may repay less than you would on the same total from one job, or repay through one job even if your combined income is low. Any overpayment can be refunded by the Student Loans Company. See our student loan calculator for projections.
Common Mistakes to Avoid
⚠️ Don't let two employers both use your full allowance. If both jobs use 1257L, you will underpay tax all year, and HMRC will collect the shortfall later, usually by adjusting next year's tax code.
🔴 Don't ignore a year-end underpayment. If you get a P800 tax calculation saying you owe tax, check it and pay or arrange how it is collected. HMRC charges interest on tax paid late at the Bank of England base rate plus 4%.
💡
Check whether Marriage Allowance applies. If you are married or in a civil partnership, one of you earns less than the Personal Allowance and the other is a basic rate taxpayer, the lower earner can transfer £1,260 of allowance. The receiving partner's code ends in M (for example
1383M) and the transferring partner's ends in N (for example
1131N). It works alongside multiple jobs. Read our guide on
Marriage Allowance for the full rules.
What About Three or More Jobs?
The same rules apply: you have one Personal Allowance in total, and HMRC can spread it across any number of PAYE jobs. A common pattern is:
- Main job: 1257L or a portion of it
- Other jobs: BR, a smaller allowance code, or D0 if your combined income is in the higher rate band
The Bottom Line
Splitting your allowance across jobs is about getting the right tax taken during the year. It does not lower your total tax bill. It is worth asking for when your main job pays less than £12,570, so you stop overpaying month by month. For most people with one main job and a smaller second job, the standard codes are already correct.
Run your numbers through our take-home pay calculator to see what your combined income should cost in tax, then compare it with what your payslips are taking.