Second Job Tax Calculator, 2026/27
Taking on a second job or a side contract often means all of that income is taxed at basic rate or higher from the first pound, because the personal allowance is usually set against the main job. This calculator shows the real take-home from a second income.
The second job tax calculator runs on the rates and thresholds HMRC has published for the 2026/27 tax year, so the figures you see reflect the position your company is actually filing on rather than a historic set of bands. Change any input and the result recalculates immediately, with no sign-up and nothing sent anywhere.
If you are a director of a UK limited company, use it as a first look before a decision rather than as the decision itself. Assumes the personal allowance and basic rate band are fully allocated to the main job's tax code, so the second job is taxed on top, which is the normal default without a coding notice. Real company positions bring in other income, reliefs, group structures and prior year adjustments that a single page of inputs cannot see, which is why the workings are written out below under personal & self assessment tax. Read those, then check the numbers against your own accounts, and speak to us if anything looks materially different from what you expected.
Last reviewed 12 September 2026 for the 2026/27 tax year. Reviewed by Waqas Sagar, Member of ICAEW, Fellow of ACCA, Fellow of AAT.
Regulated by
Regulated & AML supervisor
AAT fellow member
Xero Gold PartnerCertified advisor
QuickBooks PartnerCertified ProAdvisor100+ yearsCombined team experienceFully insuredUp to £2m indemnitySecond Job Tax Calculator
Result, 2026/27
Net income from second job
Extra tax caused by second job
Effective rate on the second job
Combined tax for the year
Illustration only, figures are based on the rates you have selected and the information entered. Please check your own position with us before acting.
Estimates for the 2026/27 tax year using published GOV.UK rates. Switch between 2026/27 and 2025/26 above.
How this is calculated
This calculator computes the total income tax due on your main salary alone, then again on your main salary plus the second income combined, and treats the difference as the tax attributable to the second job. This mirrors how HMRC actually taxes a second PAYE job, using a BR, D0 or D1 tax code that applies basic, higher or additional rate from the first pound, because the personal allowance is already assumed to be used against the main employment.
Where the combined income pushes part of it into a higher band, the extra tax rate on the second job can look much higher than expected, even though the overall calculation is exactly the same total liability as if it were one combined salary.
If your second job's income tax code is wrong, for example still carrying a personal allowance that should sit against your main job, HMRC will eventually reconcile this and either bill you or refund you the difference.
PAYE coding for multiple jobs
By default HMRC allocates your full personal allowance to whichever job it considers your main employment, usually the one that started first or pays the most, and taxes any other job at a flat rate with no allowance at all. You can ask HMRC to split the allowance across two jobs if that suits your circumstances better, though this rarely changes the total tax due over the year.
Self-employed side income is not taxed through PAYE at all; it is reported on a self-assessment return and combined with employment income there instead.
Why a second job can feel like poor value
Because the personal allowance is already used, every pound of a second job is typically taxed at 20% and full National Insurance from the outset, and if it tips total income over £50,270 the marginal rate rises to 40%. This is the same total tax as if the income had all come from one employer, but it can be surprising to see so little in the second payslip.
For side income run through a limited company instead of employment, comparing salary, dividends and retaining profit in the company can sometimes be more efficient, and is worth a separate calculation.
What this means for your company
Treat the result as a planning figure for the 2026/27 tax year. If it changes what you were about to do, take a director's salary, a dividend, a large asset purchase or a filing decision, check it against your own accounts first. We can review the position with you and confirm the tax treatment before you commit.
Frequently asked questions
Why is my second job taxed at a flat rate with no allowance?
HMRC assumes your personal allowance is already used against your main job, so a second PAYE job is usually coded BR, D0 or D1, taxing all of it at basic, higher or additional rate from the first pound.
Can I split my personal allowance between two jobs?
Yes, you can ask HMRC to allocate part of your personal allowance to each job, which changes how tax is deducted month by month but does not change the total tax due over the year.
Does National Insurance work the same way across two jobs?
No, National Insurance is generally assessed separately for each job against its own threshold, so a modest second job may attract less National Insurance proportionally than income tax.
Is side income from self-employment treated the same as a second job?
No, self-employed income is not taxed through PAYE. It is reported on a self-assessment return, combined with your employment income for income tax purposes, with Class 2 and 4 National Insurance calculated separately.
Keep going
Related calculators
Same rates, different question.
P800 Tax Checker
Check whether your PAYE tax code and total tax paid line up with your actual liability for the year, similar to the reconciliation on an HMRC P800.
CalculatorSelf Employed Tax Calculator
Calculate the income tax and Class 4 National Insurance due on your self-employed profit for 2026/27, plus what you should be setting aside.
CalculatorStealth Tax Calculator
See how frozen tax thresholds quietly increase your tax bill through fiscal drag, and where the effective 60% marginal rate trap applies in 2026/27.
CalculatorTax Refund Calculator
Estimate a PAYE tax refund for 2026/27 caused by an emergency tax code, an incomplete year of employment, or unused personal allowance.