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Business finance · 2026/27

Sole trader monthly tax reserve calculator UK

Turn a simple sole trader tax estimate into a monthly amount to put aside. Check the formula, worked example and limits before using your own figures.

Enter your figures

Your estimate

Monthly tax and Class 4 reserve

£594.32
Annual combined estimate£7,131.80
Income Tax£5,486.00
Class 4 NI£1,645.80

Use your actual figures. Any prefilled price, fee, rate or return is an editable illustration, not a current product quote. 2026/27, sole trading profit only, standard allowances and Class 4 eligibility. No other income, student loans, voluntary Class 2 or payments on account. Cash due on filing dates may differ.

How the sole trader monthly tax reserve calculator uk works

Reserve = modelled annual Income Tax plus Class 4 NI, divided by 12.

UK data and rules

2026/27 data · Checked 16 October 2026. Rules are a dated snapshot, not a live feed.

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Worked example: sole trader monthly tax reserve

This illustration uses the calculator’s example inputs. It is not a quote or a recommended financial decision.

Annual taxable trading profit (£)
40,000
Country for tax purposes
England

Monthly tax and Class 4 reserve: £594.32

Reserve = modelled annual Income Tax plus Class 4 NI, divided by 12.

Sole trader monthly tax reserve: questions answered

What does the sole trader monthly tax reserve calculation include?

Reserve = modelled annual Income Tax plus Class 4 NI, divided by 12. Use your actual figures. Any prefilled price, fee, rate or return is an editable illustration, not a current product quote. 2026/27, sole trading profit only, standard allowances and Class 4 eligibility. No other income, student loans, voluntary Class 2 or payments on account. Cash due on filing dates may differ.

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Using your result

Example inputs are a starting point. Replace them with your figures and select Calculate result. Results are rounded for display; calculations use unrounded values.

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