One of the most common questions we hear from people starting a new role, going self-employed, or considering a limited company is simple: how much will I actually take home? It sounds like a straightforward calculation, but in practice it involves several overlapping deductions — and the answer changes depending on how your income is structured.

If you want to work out take home pay with any real accuracy, it helps to understand what’s being deducted and why, rather than just plugging numbers into a calculator and hoping for the best. Online tools are a useful first step, but they can’t account for your specific circumstances — things like pension contributions, student loan repayments, multiple income sources, or whether you’re drawing a salary and dividends as a company director.

This post walks through the key components that determine your net pay, the situations where generic calculators tend to mislead, and how your employment or trading structure changes the picture significantly.

For most employees, the deductions that reduce your gross pay to net pay fall into three main categories: Income Tax, National Insurance contributions (NICs), and any voluntary or contractual deductions such as pension contributions or student loan repayments.

For the 2026-27 tax year, the personal allowance — the amount you can earn before paying any Income Tax — remains £12,570. Above that, basic rate tax of 20% applies on earnings up to £50,270. From £50,271 to £125,140 you pay 40% (the higher rate), and above £125,140 the additional rate of 45% kicks in.

Employee National Insurance is currently charged at 8% on earnings between £12,570 and £50,270, and 2% on earnings above that threshold. These rates are worth checking directly on GOV.UK each April, as they have changed several times in recent years and may change again.

Once you add a workplace pension — where the minimum auto-enrolment contribution is 5% from the employee on qualifying earnings — and any student loan deductions, the gap between your gross salary and the figure that lands in your bank account can be significant. On a salary of £39,000, for example, the difference between gross and net is typically somewhere in the region of £8,000 to £10,000 once all these deductions are applied, though the exact figure depends on your specific circumstances.

Salary calculators are built around a set of standard assumptions: one employer, no other income, a standard tax code, and earnings paid evenly across the year. When your situation matches those assumptions, they’re reasonably accurate. When it doesn’t, the numbers can drift quite far from reality.

A few common scenarios where calculators mislead:

• Commission and bonuses. If you receive a bonus in a single month, it may be taxed at a higher rate in that payslip because HMRC’s PAYE system applies tax on a cumulative basis. The annual figure may correct itself over the year, but the month-by-month numbers will look odd.
• Non-standard tax codes. If HMRC has adjusted your tax code to collect underpaid tax from a previous year, or to account for a benefit-in-kind like a company car, your take-home will be lower than a standard calculator suggests.
• Multiple income sources. Anyone with a side business, rental income, or investment income will owe additional tax that payroll doesn’t capture — and a salary calculator won’t show it.
• Student loan plan type. The repayment rate and threshold differ between Plan 1, Plan 2, Plan 4 (Scotland), and the Postgraduate Loan. Using the wrong plan type can throw calculations off by hundreds of pounds annually.

The GOV.UK tax estimator is generally more reliable for employees than third-party tools, but it still has limits if your income is variable or comes from multiple sources.

If you’re self-employed — whether as a sole trader or through a limited company — working out your take-home pay is a different exercise entirely, and it requires thinking beyond PAYE deductions.

Sole traders

As a sole trader, you pay Income Tax on your profits (not your turnover), plus Class 4 National Insurance contributions. Class 4 NI currently runs at 6% on profits between £12,570 and £50,270, and 2% above that. You also pay a flat-rate Class 2 NI if your profits exceed the small profits threshold, though the rules here have been in flux in recent years.

The key difference from employment is that you can deduct allowable business expenses before calculating your taxable profit — so two people earning the same gross revenue can have very different tax bills depending on their legitimate deductions.

Limited company directors

Directors of limited companies typically take a combination of a low salary and dividends to optimise their overall tax position. The salary is usually set around the National Insurance threshold to preserve your NI record without triggering significant NI liabilities, and the rest comes as dividends — which are taxed at lower rates than employment income.

Understanding your dividend allowance is essential here. The first £500 of dividends is currently tax-free. Above that, dividend tax rates are 8.75% (basic rate), 33.75% (higher rate), and 39.35% (additional rate) — meaningfully lower than the equivalent income tax rates.

Getting the salary/dividend split right is one of the most impactful things a good accountant does for owner-managed businesses.

Contractors sit in a particularly complicated position when it comes to understanding their take-home pay, because the mechanism through which they’re paid significantly affects what they keep.

If you work through a umbrella company, your gross contract rate is not your income — the umbrella company is technically your employer, so employer NI (currently 15% above the secondary threshold, following the April 2025 increase) is deducted from your contract rate before you even see a gross figure. This catches a lot of contractors off guard when they first make the switch from a limited company. You can use a day rate calculation to compare what different structures actually deliver in your pocket.

If you work under the Construction Industry Scheme (CIS), deductions of 20% (or 30% if you’re not registered) are made at source by your contractor. These aren’t your final tax liability — they’re advance payments towards your Self Assessment tax bill. This means CIS subcontractors often overpay during the year and receive a refund when they file their return, but the in-year cash flow impact can be painful if you’re not budgeting for it.

IR35 adds another layer of complexity for contractors who work through a personal service company. If you’re inside IR35, the tax treatment effectively mirrors employment, which substantially reduces your take-home compared with a genuine outside-IR35 engagement.

In our experience, contractors often have the most to gain — and the most to lose — from understanding how their pay structure works.