Second Job Tax: How Much You’ll Pay and Why
Find out how much tax you'll pay on a second job in the UK, how your tax code works and why more tax can come off the extra pay.
In this article
Your second job tax depends on your total income, tax code, and employment type.
Taking on a second job can be a good way to increase your income, but you may notice that more tax comes off the extra pay than you expected.
This is because you only get one Personal Allowance. Your tax also depends on your total income across both jobs, which can push some of your earnings into a higher tax band.
Here’s how second job tax works for the 2026/27 tax year.
Key points
- Your second job may have a different tax code 🧾
Seeing BR, D0, or D1 as your second job’s tax code just means HMRC has already allocated your Personal Allowance to your main job. It’s not an extra charge for working two jobs. - National Insurance is usually worked out separately per job 🧮
Unlike with Income Tax, most employers calculate your NI based on what they pay you, not your combined earnings. This can sometimes mean paying more NI overall than someone earning the same total from one job. - Combined income over £100,000 changes the maths 📈
If your two jobs push your total earnings past £100,000, your Personal Allowance starts shrinking, and the effective tax rate on that slice of income can hit 60%. It’s one of the most overlooked side effects of taking on extra work. - Keeping two income streams organised gets easier with ANNA 🚀
Between different tax codes and NI rules, you need visibility over both incomes in one place to know where you stand. ANNA brings your income, expenses, and tax estimates together so you’re not left guessing what you owe.
How is tax on a second job calculated?
For the 2026/27 tax year, the standard Personal Allowance is £12,570. This is the amount of taxable income you can receive before Income Tax normally starts.
You get one Personal Allowance for the tax year, not one for each job. HMRC looks at your income across your different jobs and other taxable sources when working out your overall tax position.
For taxpayers in England, Wales, and Northern Ireland, the main Income Tax rates for 2026/27 are:
| Tax rate | Threshold |
|---|---|
| Basic rate - 20% | Taxable income up to £37,700 |
| Higher rate - 40% | Taxable income from £37,701 to £125,140 |
| Additional rate - 45% | Taxable income above £125,140 |
These figures are different in Scotland, where Scottish Income Tax has its own rates and bands.
The Personal Allowance and basic rate limit are frozen at their current levels, with the government confirming the freeze through to 5 April 2031.
How your second job affects your tax
Your second job can push some of your income into the 40% tax band.
For example, suppose your main job pays £35,000 and your second job pays £15,000.
Your total income is £50,000. After your £12,570 Personal Allowance, you have £37,430 of taxable income. This is just below the higher rate threshold, so all of it is taxed at 20%.
Now increase your main salary to £40,000 while keeping the second job at £15,000. Your total income is £55,000, leaving £42,430 after your Personal Allowance.
The first £37,700 is taxed at 20%, while the remaining £4,730 is taxed at 40%.
So if your second job takes you into the higher rate band, only the income above the threshold is taxed at 40%.
The 60% tax trap
If your combined income from both jobs pushes you over £100,000, your Personal Allowance starts shrinking.
For every £2 of income above £100,000, you lose £1 of your £12,570 allowance, and it disappears once you reach £125,140.
Combined with the 40% higher rate, this creates an effective marginal tax rate of 60% on income in that band.
Tax codes and second jobs
Your tax code tells your employer how much tax to take from your pay.
If you have more than one job, HMRC will usually give each employer a different tax code. Your main job may get the standard 1257L code, while your second job may get a code like BR, D0, or D1, which taxes that job’s pay at a flat rate:
- BR: 20%
- D0: 40%
- D1: 45%
HMRC decides which codes to use based on your circumstances and information about your total income.
A BR tax code means your Personal Allowance is already being used against income from your main job, so the second employer deducts tax from the first pound they pay you.
What if your tax code is wrong?
Your tax code can change when you start or leave a job, and HMRC may adjust it when it receives information about your income.
If you think you’ve been given an incorrect tax code, check the details HMRC holds about your jobs and income. Until corrected, the error may result in your employer paying too much or too little tax.
Second job tax: Your National Insurance
Income Tax and National Insurance (NI) use different calculations.
When you have two jobs with different employers, each employer will calculate your employee NI separately based on what they pay you. Your second employer usually doesn’t combine your salary from your first job when working out NI.
For 2026/27, most employees pay:
- 0% on earnings up to £12,570
- 8% on earnings between £12,570 and £50,270
- 2% on earnings above £50,270
Because each job gets its own run at these thresholds, your NI bill can look quite different from your Income Tax bill.
An example of National Insurance with two jobs
Suppose you earn:
- £30,000 from your main job
- £10,000 from your second job
Your second employer looks at the £10,000 they pay you when calculating NI. As this is below the £12,570 Primary Threshold, you wouldn’t pay employee NI on that salary.
If you earned the full £40,000 from one employer, that employer would calculate NI on the amount above £12,570.
When can earnings from two jobs be combined?
If you have two jobs with the same employer, or with two employers whose businesses are associated, HMRC may require the earnings to be combined when calculating NI. In that situation, the usual separate calculation won’t apply.
What if your second income is from self employment?
If you’re both employed and self employed, you pay tax on your self employed profit alongside your income from your main job.
Your self employed profit is added to your other taxable income when working out your Income Tax. You may also have to pay Class 4 NI on your self employed profits, which is currently charged at:
- 6% on profits between £12,570 and £50,270
- 2% on profits above £50,27
If your side income isn’t more than £1,000, the trading allowance may cover it. You don’t need to report it to HMRC unless you have to file a Self Assessment tax return for another reason.
💡 Did you know?
If your second income comes from freelance work, keeping your invoices, expenses, and receipts organised from the start makes it much easier to work out your taxable profit.
ANNA’s Auto Accountant can help you record income and expenses and keep your books up to date.
Getting your tax right when you have two jobs
Whether you pay the correct amount of tax on your two jobs depends on the information HMRC holds about them, so it needs to be accurate and up to date.
Check your tax position regularly, but especially when you:
- Start or leave a job
- Get a pay rise or change your working hours
- Take on another source of income
- Stop one of your jobs
- Start earning self employed income alongside PAYE income
You can check the jobs and estimated income HMRC has on record and update anything that’s wrong. Your tax codes can then be adjusted so your PAYE deductions are closer to the amount you owe.
If you have a PAYE job alongside self employed income, dividends, savings, or property income, your tax position becomes more complicated. In those cases, it’s a good idea to speak to an accountant.
How ANNA helps when you have more than one income
Running two incomes means more to keep on top of, from tax codes and NI to a possible tax return.
ANNA brings your business account, bookkeeping, invoicing, and tax admin together in one place, so you always know where your second income stands.
Here’s what ANNA can help with:
- Real-time tax estimates: See an up-to-date picture of what you owe as your combined income changes through the year
- Automatic bookkeeping: Keep a clear record of freelance or self employed income and expenses, categorised automatically
- Dedicated UK business account: Manage your side income and spending from the same place as your bookkeeping
- Invoice creation and tracking: Create professional invoices for side work and track what’s been paid
- Receipt capture: Snap and store receipts so nothing gets missed when it’s time to work out your taxable profit
- Free Self Assessment filing: Let ANNA prepare and file your Self Assessment return directly to HMRC, built from your existing bookkeeping
- Smart Pots: Set money aside automatically so you’re not caught out when a tax bill lands
- Smart reminders: Stay on top of Self Assessment deadlines and other admin dates
- 24/7 UK-based support: Get help whenever a tax question comes up
Open an ANNA business account and keep your second income sorted alongside everything else.
FAQ
Yes. HMRC will usually give your Personal Allowance to the job it sees as your main job. This isn’t always your highest-paying job, especially if you recently started a better-paid role and HMRC hasn’t caught up yet.
If your higher-paying job is taxed at BR while your lower-paying job gets your allowance, you can ask HMRC to change your tax codes. This can move more of your Personal Allowance to the job where you earn the most.
Possibly. Each employer normally calculates your NI separately, which can sometimes mean you pay more than someone earning the same total from one job.
If you expect to earn at least £967 a week from one job and £242 a week from the other, you can apply to defer NI on the second job using form CA72A. The second employer then deducts at a reduced rate of 2%. HMRC checks your total at the end of the tax year and writes to you if you still owe anything.
If you don’t apply in advance and pay too much NI, you can claim a refund after the tax year ends.
It can. The High Income Child Benefit Charge starts when your adjusted net income goes above £60,000 and can take back all your Child Benefit once it reaches £80,000.
A second job could push your income over the £60,000 threshold, so check whether the charge applies when your total income increases.
Not necessarily. Each employer looks at the pay they give you when deciding whether you qualify for automatic enrolment.
For 2026/27, the earnings trigger is £10,000 a year. So if you earn £8,000 from one job and £6,000 from another, neither employer may have to enrol you automatically, even though your total income is £14,000.
Usually not. If both jobs are taxed through PAYE and you have no other reason to file, HMRC will normally collect the right tax through PAYE based on your tax codes.
You may need to file a Self Assessment if, for example, you have other untaxed income, you need to claim certain reliefs, or HMRC tells you to file. If the High Income Child Benefit Charge applies and PAYE is your only income, you can now choose to pay it through your tax code instead of filing a return.
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