Free Excel Download
PAYE + Side Hustle Tax Tracker 2026/27
Stack your side income on top of your PAYE salary and automatically estimate how much to set aside for tax each month.
What’s Included
- One-off salary input — enter your annual PAYE salary once, and the sheet works out which tax band your side income falls into.
- Automatic band detection — because your side income stacks on top of your employment income, it's often taxed at your highest marginal rate (20%, 40% or 45%) rather than starting from 0%. This sheet handles that automatically.
- £1,000 Trading Allowance built in — toggle whether you're using the tax-free trading allowance, and the sheet adjusts the calculation accordingly.
- Monthly set-aside tracking — log each month's side income and see exactly how much to move into a savings pot for tax.
Why Side Income Gets Taxed Differently Than People Expect
- Your Personal Allowance and basic rate band are typically used up by your PAYE salary first, meaning side income is added on top and taxed at your marginal rate, not from scratch.
- If your salary already exceeds £50,270, your side income is likely taxed at 40%, not 20% — a common and costly assumption people get wrong.
- The first £1,000 of side income each tax year is tax-free under the Trading Allowance, if you choose not to claim actual expenses instead.
- Once side income exceeds £1,000 in a tax year, you must register for Self Assessment, even if the extra tax ends up being minimal.
Frequently Asked Questions
Yes, if your side income exceeds the £1,000 Trading Allowance. Because your PAYE salary typically uses up your Personal Allowance already, side income is usually taxed at your marginal rate from the first pound above the allowance.
It depends on your total income for the year. If your PAYE salary plus side income keeps you under £50,270, side income is taxed at 20%. Between £50,270 and £125,140, it is taxed at 40%. Above £125,140, at 45%.
Yes, once your side income exceeds £1,000 in a tax year, HMRC requires you to register for Self Assessment, even if very little or no extra tax ends up being due.
Yes, completely free with no email signup required.
Sources
- Trading Allowance from GOV.UK — Tax-free allowances on trading income (checked 2026)
- Income Tax rates from GOV.UK — Income Tax rates and Personal Allowances