Not sure how taking on a second job affects your tax?
Whether you’re looking to make some extra money or trying out a new career path, taking on a second job is a great way to boost your income. But if you’re working more than one job, it’s important to understand how much second job tax you’ll need to pay.
We’ve spoken to the experts at MoneyHelper to break down everything you need to know about how tax on second jobs works:
Can my employer stop me from having a second job?
Before you start looking for a second role, the first thing to check is your current employment contract.
Some employers might have rules that prevent you from taking on extra work, especially in situations where:
- There could be a conflict of interest – for example, working for a rival company.
- Your second job might negatively affect your performance in your main job.
- The role could bring your main employer into disrepute.
If you can’t find a copy of your contract, your HR department should be able to help. If there’s nothing in your contract about having 2 jobs, then your employer can’t stop you from taking another one.
Contract of employment – key terms explained
What are my rights when working a second job?
Whether it’s your first or second job, you have employment rights.
This includes being paid at least the National Minimum Wage (or the National Living Wage if you’re 21 or over) and not being asked to work more than an average of 48 hours per week in a single job – unless you choose to.
Working hours: What you need to know
What is the National Living Wage?
How does HMRC work out second job tax?
When you have more than one job, HMRC needs to work out how much tax you should pay on your combined income.
Your personal allowance
Everyone is entitled to a personal allowance, which is the amount of money you can earn each tax year before you start paying Income Tax. For the 2025/26 tax year, the personal allowance is £12,570.
You only get one personal allowance, no matter how many jobs you have. Usually, your personal allowance is applied to your main job – the one that pays you the most. This means you’ll pay tax on all the income from your second job. It might look like you’re paying more tax on your second employment, but it’s because your tax-free allowance has already been used up.
Splitting your personal allowance
If you have two or more jobs and neither of them pays more than the personal allowance, you can ask HMRC to split your personal allowance between them. This can help you pay the right amount of tax throughout the year.
However, only do this if your income from each job is stable. If one job pays more than expected, you could end up underpaying tax and have a bill to pay at the end of the tax year.
How much tax will I pay on a second job?
To calculate second job tax, you need to consider your total earnings from all jobs.
Your income from your second job is added to your income from your main job. This combined amount determines which tax band you fall into. For 2025/26, the Income Tax rates and bands for England, Wales, and Northern Ireland are:
- Basic rate: 20% on income between £12,571 and £50,270
- Higher rate: 40% on income between £50,271 and £125,140
- Additional rate: 45% on income over £125,140
For example:
Jane has a main job paying £14,000 and a second job paying £6,000. Her personal allowance is used for her main job. She pays 20% tax on the £1,430 she earns above the allowance in her main job, and 20% tax on all £6,000 from her second job.
If your total earnings from having two jobs push you into a higher tax band, you’ll pay the higher rate on the portion of your income that falls into that band.
What is a second job tax code?
Your tax code tells your employer how much tax to deduct from your pay. For your second job, you’ll likely be put on a ‘BR’ tax code.
What does a BR tax code on a second job mean?
BR stands for ‘Basic Rate’. This code means all your income from that job will be taxed at the basic rate of 20%, with no personal allowance applied. This is the most common 2nd job tax code.
If your total earnings push you into the higher or additional tax bands, your second employment tax code might be ‘D0’ (for the 40% higher rate) or ‘D1’ (for the 45% additional rate).
It’s really important to check your tax codes are correct for both jobs to avoid paying the wrong amount of tax. You can find your tax code on your payslip.
How to avoid paying the wrong amount of tax
When you start a second job, your new employer will give you a ‘starter checklist’ form (which used to be called a P46). On this form, you’ll need to declare that you have another job. This information helps HMRC give you the correct tax code.
Mistakes can still happen, so always check your payslips and tax codes.
You could be paying too little tax if:
- You haven’t told HMRC you have a second job and you’re getting a personal allowance for both.
- Your combined income pushes you into a higher tax band, but you’re paying the basic rate on both incomes.
You could be paying too much tax if:
- The total income from your two jobs is less than your personal allowance, but you’re being taxed on one of them.
If you think you’ve been paying too much tax, you can claim a refund from HMRC.
Tell HMRC if you have a new job or more than one job
Paying too much tax? Here’s what to do next
What about National Insurance and pensions?
When you have 2 jobs and tax is on your mind, don’t forget about National Insurance and pensions.
National Insurance on a second job
You pay National Insurance on each job separately. If you earn above the threshold (£242 a week for 2025/26) in both jobs, you’ll pay National Insurance contributions on both.
Second jobs and pensions
If your second job offers a workplace pension, you can pay into it. Just remember to keep track of the details, as it can be easy to forget about smaller pension pots. When you leave that job, you might be able to combine it with your other pensions.
Workplace pension laws: What you need to know
Frequently asked questions
Here are the answers to some common questions about second job tax.
How do I calculate my second job tax?
The easiest way to get an estimate is to use an online tax calculator. For an exact figure, you’ll need to know your total annual income from all jobs and your tax codes. You can also find your tax information in your personal tax account on the GOV.UK website.
What if my second job is self-employed?
If you’re self-employed in your second job, the tax rules are different. You’ll need to register as self-employed with HMRC and file a Self Assessment tax return each year. You’ll be responsible for paying your own tax and National Insurance on your self-employed earnings.
How does having 2 part time jobs affect tax?
The tax rules are the same whether your jobs are full-time or part-time. Your tax is based on your total income from all jobs combined. HMRC will usually apply your personal allowance to one job and tax the other at the appropriate rate.
If you have 2 jobs, do you pay more tax?
You don’t pay ‘more’ tax just for having two jobs. You pay the same amount of tax on your total income as you would if you earned that same amount from a single job. The main difference is how the tax-free personal allowance is applied.
Ready to find a second job? View all available part-time jobs now.
