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Second Job Tax Calculator 2024
with Combined Income Breakdown

Find out how much tax you pay on a second job. Your second income is taxed on top of your first, meaning more of it falls into higher brackets. See the exact cost for Netherlands, UK, and US.

Country
💼
Netherlands Second Job Tax
Your Main Job
€
Your annual gross salary from your primary employment.
Your Second Job
€
Annual gross from second job, freelance work, or side income.
%
Employee pension deduction applied to main job only. Reduces loonheffing base on main income.
code
HMRC assigns a tax code to your second job. BR is the most common default. Check your P45 or contact HMRC if unsure.
toggle
Scottish rates apply for income tax. National Insurance is UK-wide.
status
Affects the federal tax brackets applied to combined income.
%
Flat state rate on all income. Leave at 0 for no-income-tax states (TX, FL, WA, etc.).
Tax on Second Job Income
—
annual deduction
Net Second Job Income
—
after tax & social
Effective Rate on Second Job
—
tax ÷ second income
Marginal Rate
—
on second income
Monthly Net Second Job
—
take-home per month
Total Combined Net
—
both jobs after tax
Full Tax Breakdown — Second Job
Main Job Only
Gross salary—
Income tax—
Social contributions—
Net take-home—
Effective rate—
✚ With Second Job
Combined gross—
Total income tax—
Total social—
Combined net—
Combined effective rate—
Net Second Income at Different Earnings Levels
Second Job Gross Tax on 2nd Job Social (2nd) Net 2nd Job Eff. Rate
Combined Income: Where It All Goes
Net (main job)
Net (second job)
Tax (main)
Tax (second)
Social (main)
Social (second)
Estimate only. This calculator uses 2024 simplified rules. For the Netherlands, loonheffingskortingen are applied only to the main employer. UK tax codes depend on HMRC assignment and may differ. US calculations use annual combined income and the standard deduction is applied once across both jobs. Always verify with a tax adviser.
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💡 Why second jobs are taxed more

Your personal allowance and tax-free credits are used up by your main job first.
Second income sits on top of your main salary, so it lands in a higher tax bracket.
In the UK, a second employer deducts tax at a flat rate (usually 20%) because they have no allowance to apply.
In the Netherlands, the arbeidskorting is only applied via one employer (loonheffingskorting).
You may still receive a refund or owe additional tax when you file your annual return.

Related Calculators

Payroll Tax Calculator→ Gross to Net Calculator→ Bonus Tax Calculator→ Net to Gross Calculator→ Salary Sacrifice (NL)→

Related Guides

Second Job Tax Explained→ UK Second Job Tax Codes→ Second Job in the Netherlands→

Why a second job is taxed differently

When you take a second job, your personal tax-free allowances and credits are already consumed by your main employer. The second employer has no allowance left to apply, so your second income is taxed from the first pound, euro, or dollar at your marginal rate — the rate that applies to the top slice of your total earnings.

This does not mean the tax system penalises second jobs unfairly. It simply reflects the fact that progressive tax applies to your total annual income, not to each job separately. Whether you earn all your income from one employer or split it across two, the total tax liability is the same — the difference is how it is collected during the year.

How each country handles it

CountryWithholding methodPersonal allowanceSettlement
NetherlandsMarginal Box 1 rate via bijzonder tariefKortingen on main job onlyAnnual aangifte (tax return)
United KingdomFlat BR (20%), D0 (40%), or D1 (45%) codeFully used by main job (1257L)HMRC self assessment or PAYE adjustment
United StatesAggregate — based on total annual incomeStandard deduction applied onceAnnual Form 1040 filing

Frequently Asked Questions

Will I always pay more tax on a second job than a first?+
Yes, in the sense that each unit of second job income is taxed at a higher marginal rate than the early units of your main job income, which benefited from the tax-free personal allowance and lower rate bands. However, your total annual tax bill is the same whether you work one job or two with identical combined income — the difference is timing and withholding method, not total liability.
What is a BR tax code in the UK and can I change it?+
BR stands for Basic Rate and means HMRC has instructed your second employer to deduct income tax at 20% on all earnings from that job, with no personal allowance applied. This is the default code for most second jobs. You can request a different code from HMRC if you believe your personal allowance is not fully used by your main employment, for example if your main job income is below the personal allowance threshold.
Do I pay National Insurance on a second job in the UK?+
Yes. National Insurance is calculated separately for each employment. Each employer applies the primary and upper earnings limits independently. This means that if your earnings from both jobs are below the primary threshold individually, you may owe less NI overall than the combined calculation shows. If each job separately exceeds the primary threshold, both will deduct NI, and you may overpay and be entitled to a refund at the end of the tax year.
How is a second job handled in the Netherlands?+
In the Netherlands you should only activate the loonheffingskorting (wage tax credits, including the algemene heffingskorting and arbeidskorting) with your main employer. Your second employer should withhold loonheffing without these credits, which means the second income is effectively taxed at the marginal Box 1 rate. If you incorrectly activate credits with both employers you will underpay and will owe the difference when you file your annual belastingaangifte.
Is it worth taking a second job given the tax cost?+
That depends on your marginal rate and the value of your time. If your combined income puts you in a 40% tax bracket, you keep 60 cents of every extra pound earned, before any social contributions. At very high incomes the UK personal allowance taper creates a 60% effective rate on income between £100,000 and £125,140. For most people earning moderate incomes the net return on a second job is still meaningful. The key is to calculate the actual net income rather than the headline rate, which is what this calculator does.