Tax year 2026/27

The Side Hustle Tax Calculator

Plug your numbers in. We work out exactly what HMRC will want for the 2026/27 tax year, when they will want it, and which rate each pound of your income falls into. Handles dividends, Scottish bands, tax codes, the £1,000 trading allowance, and the first-year Self Assessment payment schedule.

By Justin Logan · Verified against gov.uk and HMRC for the current tax year

Your numbers

Day job salary, gross per year

Earnings before tax from your employer. Leave blank if you have none.

Side hustle income, gross per year

Total takings from self-employment before any expenses are deducted.

Side hustle expenses, per year

We pick whichever saves you more: actual expenses or the £1,000 trading allowance.

Dividend income, per year

UK dividends outside an ISA, including from your own limited company.

Tax code (optional)

Defaults to 1257L (standard). Accepts L, M, N, K, BR, D0, D1, NT codes.

Scottish taxpayer · uses Scottish bands 19-48% Income from a connected party · trading allowance does not apply First year of Self Assessment · shows the payment schedule

Enter your numbers to see the breakdown.

What next

Calculator

Trading Allowance Calculator

Step back and check whether your gross income is even above the £1,000 threshold, or whether expenses beat the allowance.

Open calculator › Read next

How much tax do you pay on a second income?

The plain English explainer for what the calculator just told you, with worked examples and tax-band breakdowns.

Read article › Read next

Do I need to tell HMRC about my side hustle?

When the £1,000 trading allowance covers you, when Self Assessment kicks in, and exactly what triggers a tax bill.

Read article › Template

SA Registration Checklist

If your side hustle is over £1,000, this 12-step checklist walks you through registering with HMRC, with all the gov.uk links inline.

Open checklist ›

Key terms

PAYE

· Pay As You Earn, the tax your employer deducts from your salary automatically

Self Assessment

· the annual UK tax return you file if you have income outside PAYE

Personal Allowance

· tax-free amount of income (£12,570 for 2026/27)

National Insurance

· UK social security contribution, paid alongside Income Tax

Class 4 NI

· National Insurance paid by self-employed people on their profit

Trading Allowance

· £1,000 tax-free amount for small-scale self-employment income

Payment on Account

· advance instalment toward next year's tax, due 31 Jan and 31 Jul

Connected party

· your own limited company, employer, or partnership you are a partner in

Dividend allowance

· £500 of dividend income taxed at 0% per year

Form SA303

· the HMRC form to reduce your Payments on Account in advance

This calculator is a guide based on published HMRC and gov.uk rules for the 2026/27 UK tax year. It does not constitute personal tax advice. Some life situations are not handled here (partnership income, capital allowances, pension contributions, student loan repayments, the High Income Child Benefit Charge, Marriage Allowance transfers, property income, savings income). For your specific circumstances, consult HMRC directly or speak to a qualified UK accountant. Sources: gov.uk Income Tax rates, Scottish Income Tax, Self-employed NI rates, Tax on dividends, Trading allowance, Payments on Account.