Second Job Tax: How Much Will You Actually Pay?

How Second Job Tax Actually Works 

You do not receive a separate Personal Allowance for each job. 

For 2026/27, the standard UK Personal Allowance remains £12,570. HMRC normally applies this through tax code 1257L on your main employment.

Your second employer usually deducts Income Tax from the first pound because your main job already uses the allowance.

However, your total annual income determines the correct tax rate.

These bands apply to England, Wales, and Northern Ireland, assuming the standard Personal Allowance. Higher earners may lose some or all of their allowance.

Source: GOV.UK Income Tax rates 

BR, D0 and D1: What Your Second Job’s Tax Code Means 

Your tax code tells your employer how much Income Tax to deduct.

HMRC commonly uses the following codes for second jobs:

For example, BR means your second employer deducts 20% Income Tax from every pound earned.

However, BR is not automatically wrong simply because the deductions seem high.

If your second job crosses multiple tax bands, HMRC may use a different code to collect the correct amount.

Source: GOV.UK Tax Code Guidance.

For related guidance, read our article on how an emergency tax code could mean you’re paying too much tax.

Worked Example: Two Jobs, Two Outcomes

Let’s compare two employees working multiple jobs during 2026/27.

Both examples assume standard allowances, full-year employment, and no additional taxable income. Figures exclude National Insurance.

Scenario A: Your Second Job Is Taxed Correctly

You earn £30,000 from your main job and another £8,000 from weekend work.

Your combined income is £38,000, keeping you within the basic-rate band.

The calculation works because your second income remains within the basic-rate band.

Result: BR is appropriate, and you do not owe extra Income Tax from these earnings.

Scenario B: Your Second Job Is Undertaxed

Now imagine your main job pays £55,000 annually.

Your second job pays another £15,000, bringing combined income to £70,000.

However, your second employer initially uses BR instead of D0.

Your second job should attract 40% Income Tax because your main salary already exceeds £50,270.

That creates a potential £3,000 shortfall if BR remains throughout the year.

HMRC receives payroll information through Real Time Information (RTI) and can issue a corrected code.

However, corrections may take time. Check your tax code rather than assuming HMRC has already updated it.

Try our Artifin Salary Calculator to estimate your take-home pay.

Note: Check that the calculator uses 2026/27 settings before relying on its results.

National Insurance on a Second Job

National Insurance works differently from Income Tax when you have two jobs.

Employers generally calculate Class 1 National Insurance separately for each employment.

For 2026/27, standard employee rates are:

• 8% on earnings between £12,570 and £50,270 annually, using equivalent pay-period thresholds.
• 2% on earnings above £50,270.

For example, you earn £30,000 from your main job and £8,000 from your second employment.

Your main employer deducts National Insurance from qualifying earnings.

However, your second job would normally attract no employee National Insurance because its earnings fall below the threshold.

This differs from Income Tax, which ultimately considers your combined taxable income.

Special rules can apply if you have multiple high-paying jobs. You may qualify to defer contributions or request a refund where appropriate.

Source: GOV.UK National Insurance rates and National Insurance deferment.

Do You Pay More Tax Overall for Having Two Jobs?

No. Having two jobs does not automatically increase your total Income Tax.

If both tax codes work correctly, earning £40,000 across two jobs generally produces the same Income Tax as one £40,000 salary.

The difference lies in how employers deduct tax throughout the year.

Problems arise when HMRC assigns an incorrect code or receives outdated employment information.

You could pay too little during the year and face an unexpected bill.

Alternatively, you might overpay and become entitled to a refund.

Remember, pension contributions and other deductions can affect the final calculation.

Splitting Your Personal Allowance Between Two Jobs

You can ask HMRC to split your Personal Allowance if your main job does not use it fully.

This commonly helps people working two part-time jobs.

For example, suppose your first job pays £8,000 and your second pays £7,000 annually.

Neither salary exceeds £12,570 individually, but your combined income reaches £15,000.

Your correct annual Income Tax would normally be £486.

Without the right allowance allocation, your second employer might deduct more tax than necessary.

You can request an adjustment through HMRC’s Income Tax helpline. Check your employment information through your Personal Tax Account.

HMRC can then review your tax codes and allocate the unused allowance appropriately.

Source: GOV.UK How Tax Works With More Than One Job.

Self-Employed Side Income: A Different Set of Rules

Freelance income does not automatically follow the same rules as a second PAYE job.

If you earn money through self-employment, you may need to report profits through Self Assessment.

The £1,000 Trading Allowance

For 2026/27, the trading allowance remains £1,000 annually.

If your gross trading income stays within this amount, you normally do not need to register for Self Assessment solely for that income.

However, exceptions apply.

If your gross trading income exceeds £1,000, you generally need to register and report it.

You can usually deduct eligible business expenses or claim the trading allowance when calculating taxable profits.

Your taxable self-employed profits then combine with your employment income for Income Tax purposes.

Source: GOV.UK Trading Allowance.

Self-Employed National Insurance

For 2026/27, Class 4 National Insurance generally applies at:

• 6% on self-employed profits above £12,570 up to £50,270.
• 2% on profits above £50,270.

You no longer pay compulsory Class 2 contributions under the standard rules.

If profits reach £7,105, HMRC normally treats Class 2 contributions as paid.

Those earning below this threshold may pay voluntary Class 2 contributions at £3.65 weekly.

Source: GOV.UK Self-Employed National Insurance.

Our Self-Assessments service helps individuals report additional income and meet HMRC requirements.

Common Mistakes That Cost Second-Job Earners Money

Having two jobs can create tax complications, especially when employment circumstances change.

1. Assuming BR Is Always Wrong

BR is a standard code for second jobs. Check your combined annual earnings before requesting a change.

2. Not Updating HMRC When a Job Ends

An old employment record can affect your tax code. Update HMRC when you leave an employer.

3. Ignoring a P800 Tax Calculation

HMRC may issue a P800 after reviewing your annual Income Tax.

Check whether it shows an underpayment or refund.

4. Forgetting Freelance Income

Freelance work may require Self Assessment rather than another PAYE tax code.

Check the trading allowance and registration rules.

5. Not Budgeting for Higher-Rate Tax

Your second income could push your combined earnings above £50,270.

Set aside money if your current PAYE deductions do not cover the higher liability.

How to Check and Fix Your Tax Code

You can check your tax code directly on your payslip or through HMRC.

Start by reviewing both employers’ details in your Personal Tax Account.

Then confirm whether HMRC has allocated your Personal Allowance correctly.

If something looks wrong, update your estimated annual income or contact HMRC.

Have these details ready:

• Both employers’ PAYE reference numbers
• Your estimated annual earnings from each job
• Your current tax codes and recent payslips

HMRC normally updates your employer after issuing a revised tax code.

If you manage employees, our Payroll Services can help you maintain accurate PAYE records.

Source: GOV.UK Updating Your Employment Details.

Final Thoughts

A second job does not automatically mean paying more Income Tax. Your combined earnings determine the final liability.

Checking your tax codes early can prevent overpayments and unexpected bills.

At Artifin Accountants, we help individuals understand their PAYE position and manage additional income.

Contact Us to discuss your tax circumstances.