Self-Employed Tax Calculator 2026
Estimate how much self-employed tax you'll pay
Working out your tax bill for self-employment
Being self-employed and managing your own tax affairs means it’s important to set aside money throughout the year to cover your tax bill. Enter the total amount of income you get from self-employment, how much you spent on business expenses, and the total amount of any other income you get in the same tax year.
Our free calculator will use this information to estimate how much self-employed income tax and National Insurance you’ll pay, helping you plan ahead and save the right amount in advance to avoid any nasty surprises! For simplicity, the calculator assumes any additional income hasn’t been taxed yet.
Why does the income tax calculator mention Payments on Account?
Payments on Account (POA) are advance payments towards your next tax bill. They’re mandatory if your self-employed tax bill comes to more than £1,000 or less than 80% of your total tax bill was deducted at source (such as through PAYE).
The system is designed to help you pay your tax bill by spreading tax payments across the year, although it can be a shock the first time you encounter them! Our free income tax calculator will include payments on account in your tax bill estimate. Learn more about how these are calculated.
How will I pay self-employed tax?
There are different ways to pay your tax bill, such as:
- By debit or credit card online
- Through your online bank account
- At your bank or building society
- Online or telephone banking
- Through your tax code
FAQs
You’ll normally need to register as self-employed if you earn more than the £1,000 Trading Allowance from self-employment in a tax year. If you do need to register, make sure you have everything set up by 5th October in your second tax year. For example, if you start trading in 2025/26 (6th April 2025 - 5th April 2026), you’ll need to sign up as self-employed no later than 5th October 2026.
It depends on how you file your return. Paper returns are due 31st October. Online returns have a little longer – due by 31st January.
For example, the deadlines to file a tax return for the 2025/26 tax year are:
- 31st October 2026 for a paper return
- 31st January 2027 to submit online
The key deadline for self-employed individuals to pay tax is 31st January! You might also need to make a second payment by 31st July if you need to make advance payments on account. So, if you owe tax for 2025/26 then the payment deadline is 31st January 2027. Then, if you owe payments on account you’ll need to make another payment by 31st July 2027.
You might be able to request HMRC for a Time to Pay arrangement, where the bill is spread over monthly instalments even once the deadline has passed. Make sure you contact HMRC as soon as possible if you want to request this.
Yes! It’s a legal requirement to keep records which explain the figures you enter on your tax return – and HMRC can ask for them at any point. This includes recording your income, expenses, invoices and bank statements.
Yes! Claiming all of the business expenses you’re allowed to will help reduce the amount of tax you pay, as will claiming any allowances or other types of tax relief. Some business owners find that using a different type of business structure is useful too. You can compare your tax bill as a sole trader and limited company on our free calculator.
You might need to pay Income Tax and National Insurance as a self-employed person, but there might be other types of tax which affect you, too! For example, employer NI if you hire someone else, or VAT if you reach the registration threshold. Read our tax rates article to learn more.
Looking for more information?
We have a comprehensive range of free resources available
Bookkeeping Guide
Learn the basics of bookkeeping to help you stay on top of the finances and make well-informed decisions in your business.
4 minutes
Claiming Business Expenses Guide
The topic of what business expenses you can claim for is a complex one. Let our easy to understand guide explain it for you.
5 minutes
Quick Tax Saving Tips Guide
Our guide to helping you and your business save money and operate in the most tax efficient way possible.
2 minutes
