Advanced Taxation (UK) · Alternative ways of achieving personal or business outcomes and their tax consequences

Incorporation vs Remaining Unincorporated: Tax Comparison for ACCA ATX

Updated 11 October 2026 · Fact-checked

To compare incorporation with staying unincorporated, work out the total tax and the cash left in the owner's hands under each option. Unincorporated: income tax and NIC on profits. Incorporated: corporation tax, then tax and NIC on salary, dividends or other extraction. Compare after-tax cash, then add non-tax factors.

Understand Incorporation vs Remaining Unincorporated: Tax Comparison

A sole trader or partner is taxed on the business profit whether or not they take money out. The profit is taxed as trading income at income tax rates, with NIC on top. Nothing extra happens when cash leaves the business.

A company is a separate taxpayer. It pays corporation tax on its profits. The owner is taxed again only on what they take out. Salary is taxed under employment rules (income tax plus NIC for the employee and the company). Dividends are taxed at the dividend rates and are not deductible for the company. So there are two layers of tax if you take everything out, and none on the owner if you leave profit in the company.

That is why the comparison always has two parts: tax at the business level and tax at the owner level. Profit left in the company only gets the first layer. Profit extracted gets both. The best answer usually depends on how much cash the owner actually needs.

Corporation tax has two rates. The small profits rate is 19% and the main rate is 25%. Marginal relief sits between the lower limit of £50,000 and the upper limit of £250,000. The limits are divided by the number of associated companies (including the company itself) and reduced for short accounting periods. The test uses augmented profits, which are taxable total profits plus dividends received from non-group companies.

On the income tax side, remember the cap on income tax reliefs. Unless otherwise restricted, reliefs are capped at the higher of £50,000 or 25% of income. This matters when a sole trader wants to set an early trading loss against general income. A company has no such cap on its trading loss relief in the same way, which is a point to make when comparing.

Finally, say what the figures leave out: limited liability, losses, capital gains on incorporation, business reliefs, pension contributions, and the cost and admin of running a company. Examiners reward the comparison and a clear recommendation.

Key rules to remember

Corporation tax rates: Profits ≤ lower limit: 19%. Profits ≥ upper limit: 25%. In between: 25% with marginal relief; Lower limit £50,000, upper limit £250,000, for a standalone company with a 12-month period.
Marginal relief: (Upper limit − Augmented profits) × 3/200 × Taxable total profits ÷ Augmented profits; Deduct from corporation tax at 25%. Use limits adjusted for associated companies and short periods.
Adjusted limits: Limit ÷ (1 + number of other associated companies); short period: limit × months ÷ 12; Apply both adjustments together where they both arise.
Augmented profits: Taxable total profits + dividends received from non-group companies; Used only for the rate test and marginal relief. Tax is charged on taxable total profits.
Dividend rates and nil rate: Basic 8.75%, higher 33.75%, additional 39.35%; dividend nil rate band £500; Dividends are not tax deductible for the company. The nil rate band still uses up part of the band.
Cap on income tax reliefs: Cap = higher of £50,000 or 25% of income; Applies unless the relief is otherwise restricted or not subject to the cap.
Income tax bands: Basic £1 to £37,700 at 20%; higher to £125,140 at 40%; additional above that at 45%; Personal allowance £12,570, reduced to zero when adjusted net income is £125,140 or more.

How to solve Incorporation vs Remaining Unincorporated: Tax Comparison questions

Use the same layout every time so the comparison is clear and you pick up the method marks.

1Read the requirement and note the facts: profit level, other income, whether the owner needs cash, associated companies, and the period.
2Work out the unincorporated position: taxable trading profit, income tax (with allowance and bands), and NIC from the tax tables.
3Work out the company position: profit after any salary and employer NIC, then corporation tax at the correct rate or with marginal relief.
4Apply the right limits: divide by associated companies, time-apportion short periods, and use augmented profits for the rate test.
5Work out the owner's tax on extraction: employment income tax and NIC on salary, dividend tax on dividends, using the nil rate band.
6Compare the after-tax cash (or total tax) under each option and state the difference clearly.
7Add relevant non-tax and wider tax points, such as limited liability, loss relief, the cap on reliefs, pensions, and CGT on incorporation.
8Finish with a reasoned recommendation, noting your assumptions.

Quickest way: Total tax and net cash table

When to use it: Use this for a numerical comparison when time is short and you need to show a clear gap between two options.

Write two columns: unincorporated and company.
Start both with the same pre-tax profit.
Company column: corporation tax first, then the owner's tax on the cash extracted.
Unincorporated column: income tax and NIC on the full profit.
Total each column and show net cash left; subtract one from the other.
Write one line on what would change the answer, such as profit left in the company.

Common mistakes in Incorporation vs Remaining Unincorporated: Tax Comparison

Using the full £50,000 and £250,000 limits when the company has associated companies.
Students forget to read the scenario for other companies under common control.
Fix: Count associated companies first and divide both limits by one plus the number of others.
Taxing dividends received from unconnected companies in the company's computation.
They confuse taxable profits with augmented profits.
Fix: Leave such dividends out of taxable total profits but add them to augmented profits for the rate test and marginal relief.
Deducting dividends paid as a cost when calculating corporation tax.
Salary is deductible, so students assume dividends are too.
Fix: Dividends are paid out of post-tax profit. Only salary and employer NIC reduce the profit.
Forgetting the second layer of tax when profit is extracted.
They stop after corporation tax and think the comparison is done.
Fix: Always tax the owner on salary or dividends and compare cash in hand, not just company tax.
Setting a trading loss against general income without checking the cap on income tax reliefs.
They remember the loss rules but not the limit.
Fix: Compare the relief with the higher of £50,000 or 25% of income and restrict the excess.
Recommending a structure on tax figures alone.
The calculation feels complete and the written part is rushed.
Fix: Add limited liability, admin, extraction needs, loss use and any CGT on incorporation before you conclude.

Worked examples

Example 1

A single company with no associated companies has a 12-month accounting period. Taxable total profits are £180,000 and it received no dividends. Calculate its corporation tax.

Show the solution

Profits £180,000 lie between £50,000 and £250,000, so marginal relief applies.
Tax at main rate: £180,000 × 25% = £45,000.
Marginal relief: (£250,000 − £180,000) × 3/200 × (£180,000 ÷ £180,000) = £70,000 × 0.015 = £1,050.
Corporation tax: £45,000 − £1,050 = £43,950.

Answer: Corporation tax is £43,950.

Example 2

Taxable total profits are £100,000 for a company with one associated company (two companies in total), 12-month period. It also received £20,000 of dividends from an unconnected company. Calculate its corporation tax.

Show the solution

Limits are divided by 2: lower limit £25,000 and upper limit £125,000.
Augmented profits: £100,000 + £20,000 = £120,000, which lies between the limits, so marginal relief applies.
Tax at main rate on taxable total profits: £100,000 × 25% = £25,000.
Marginal relief: (£125,000 − £120,000) × 3/200 × (£100,000 ÷ £120,000) = £5,000 × 0.015 × 0.83333 = £62.50.
Corporation tax: £25,000 − £62.50 = £24,937.50.

Answer: Corporation tax is £24,937.50.

Example 3

Ignoring NIC, compare the income tax and corporation tax cost of £40,000 of profit for a sole trader who is already a higher rate taxpayer with the same profit earned in a company that pays it all out as a dividend. The owner has not used the dividend nil rate band and the company has no associated companies.

Show the solution

Sole trader: £40,000 × 40% = £16,000 income tax, leaving £24,000 before NIC.
Company: profit £40,000 is below £50,000, so corporation tax is £40,000 × 19% = £7,600.
Profit after tax available for dividend: £40,000 − £7,600 = £32,400.
Dividend tax: the first £500 is covered by the dividend nil rate band. The balance £31,900 × 33.75% = £10,766.25.
Total tax: £7,600 + £10,766.25 = £18,366.25. Cash left: £40,000 − £18,366.25 = £21,633.75.
Compare: £24,000 against £21,633.75, before NIC. The company route costs more when all profit is extracted.

Answer: Before NIC, the sole trader keeps £24,000 and the owner of the company keeps £21,633.75. The company's advantage appears only if profit is left in the company or NIC savings outweigh the extra tax.

Exam tips

Show the structure in the first lines: two layers of tax for a company, one for an unincorporated business.
Check for associated companies and short accounting periods before you use any corporation tax limit.
Use the tax tables for NIC and dividend rates rather than learning them. Spend the time on layout and assumptions.
State assumptions clearly, for example that the owner is a higher rate taxpayer or that all profit is extracted.
End with a recommendation and at least two non-tax factors, because the professional skills marks reward judgement.

Practice questions from Alternative ways of achieving personal or business outcomes and their tax consequences

Incorporation vs Remaining Unincorporated: Tax Comparison: frequently asked questions

Is a limited company always more tax-efficient than a sole trader?

No. If the owner needs to extract all the profit, the two layers of tax can leave less cash than being unincorporated. A company helps most when profit can be left in it or taxed at the lower corporation tax rate.

How do associated companies affect marginal relief?

They reduce both the £50,000 and £250,000 limits by dividing them by the number of companies, including the one you are testing. A smaller upper limit means marginal relief starts at lower profit levels.

What is the cap on income tax reliefs?

Unless otherwise restricted, certain reliefs are capped at the higher of £50,000 or 25% of income. It can limit a sole trader who tries to set a large trading loss against other income.

Are dividends deductible for corporation tax?

No. Dividends are paid from profits after corporation tax. Only salary and related employer costs are deductible in computing the company's taxable profits.