UK second job tax calculator 2026/27
Compare the tax left from an employed second job with freelance income alongside your main role.
How the Second job estimate works
This comparison puts extra employed pay and freelance profit above your main income, then measures the additional Income Tax and National Insurance. It is an annual liability view, so PAYE deductions can look different during the year.
Rules checked
Read the checking method
What the result includes
- Incremental Income Tax from the extra work
- Employee NI for an employed role or Class 4 NI for freelance profit
- A like-for-like annual take-home comparison
What to have ready
- Expected gross pay from the second job
- Freelance turnover and allowable costs, if relevant
- Main-job taxable pay and Income Tax region
Questions about Second job
Why might payroll deduct a different amount?
PAYE uses the tax code and pay-period figures available to the employer. A second job may use BR, D0, D1 or another code, and the final annual position can differ.
Does freelance income use the same National Insurance rules?
No. A genuine sole-trader activity is based on taxable profit and may attract Class 4 National Insurance; an employment uses employee Class 1 rules.
About this estimate
Payroll tax codes and pay frequency can make the amount deducted in-year differ from this annual view.