13 February 2026 · 7 min read ·High Earners

Marginal Tax Rate Explained for UK Employees

A practical guide to effective vs marginal rates and why pay rises can feel smaller than expected.

Summary

Marginal rate explains why a pay rise can feel smaller than expected. This guide separates marginal and effective rates so salary decisions stay realistic.

At-a-glance examples (2025/26)

Typical default outputs for quick context.

Gross salaryNet monthlyNet annualOpen
£30,000 £2,093.30 £25,119.60 View page
£50,000 £3,293.30 £39,519.60 View page
£100,000 £5,713.12 £68,557.40 View page

Progressive tax means slices, not one flat rate

A frequent misunderstanding is that moving into a higher tax band means your whole salary is taxed at the higher rate. It does not. Only the portion above the threshold moves to the next rate.

This matters because salary decisions near thresholds should be based on net gain, not fear of entering a new band. In most cases, earning more still means taking home more, even if the marginal slice is taxed at a higher rate.

When comparing offers, use effective tax rate and monthly take-home rather than headline salary only. That gives a more honest view of quality of life impact.

Personal allowance taper and why it feels sharp

The personal allowance taper between GBP 100,000 and GBP 125,140 creates an effective high marginal burden because allowance is withdrawn while higher rate tax also applies. This catches many people by surprise.

For planning, test salary, bonus and pension contribution scenarios in one place. Pension salary sacrifice can reduce taxable pay and sometimes improve net outcomes in taper territory.

The right move depends on your full context, but visibility is the first step. If you cannot model it quickly, you are making decisions with incomplete numbers.

Use the calculator for practical scenarios

Guide FAQ

What is the difference between marginal and effective tax rate?

Marginal tax rate applies only to your next pound of earnings, while effective tax rate is total deductions divided by total gross income. Marginal rate is useful for pay rise planning; effective rate is better for annual budgeting. You need both views to understand day-to-day impact and longer-term compensation outcomes.

Why might a pay rise feel smaller than expected?

A pay rise can push part of your income into a higher tax band, and student loan plus pension contributions may apply to that extra slice as well. The result is that the increase in net pay can be much lower than the headline gross increase. This is normal and reflects marginal taxation, not payroll error.

How should I evaluate a job offer near a threshold?

Run scenarios slightly below and above the threshold, then compare net monthly difference. This shows whether the offer creates a meaningful cashflow improvement after deductions. Include pension and loan settings to avoid misleading comparisons.

Can I test this guide topic in the calculator?

Yes. Use the scenario links in this guide to open prefilled states, then adjust salary, region, loan and pension settings.

Are these guide pages server-rendered for indexing?

Yes. Core content is rendered in HTML and linked to salary/city/tool pages for crawlable internal navigation.

Which assumptions are most important for accuracy?

Tax region, tax code, student loan plan, pension contribution and salary sacrifice are the key assumptions to check first.

Related guides

Sources