Moving from a sole trader business to a limited company can be an important step for a business owner. But when a business and its assets are transferred to a company, the transfer can create a Capital Gains Tax (CGT) liability.

This is where Incorporation Relief can become important.

In simple terms, the relief can defer some or all of the capital gain arising when a qualifying business is transferred to a company in exchange for shares. Instead of paying CGT on the full gain immediately, the gain is generally reflected in a reduced base cost of the shares received.

However, there has been an important change from 6 April 2026 for qualifying business transfers taking place on or after this date, the relief must be claimed. It is no longer automatically given.

What is Incorporation Relief?

Incorporation Relief is a form of Capital Gains Tax relief available when an individual or partnership transfers a qualifying business to a company.

Broadly, the business must be transferred as a going concern, together with all of its assets other than cash, and the transfer must be wholly or partly in exchange for shares in the company.

Without the relief, transferring business assets to a connected company can potentially create a chargeable gain based on market value.

For example, imagine a sole trader transfers business assets that originally cost £20,000 and have a market value of £50,000 when the business is incorporated.

The potential gain would be:

£50,000 – £20,000 = £30,000

Without appropriate relief, that gain could create an immediate CGT liability.

Where Incorporation Relief applies, the qualifying gain can instead be deferred.

How does the relief work?

The relief generally works by reducing the acquisition cost of the shares received by the amount of the gain that has been deferred.

Example: Transfer entirely for shares

Peter incorporates his sole trader business and transfers the business and its assets to P Ltd.

The business is valued at £50,000 and Peter receives 1,000 ordinary shares in return.

His original cost in the relevant assets was £20,000, creating a gain of:

£50,000 – £20,000 = £30,000

If Peter makes a valid claim for Incorporation Relief, the £30,000 gain is deferred.

The £30,000 deferred gain reduces the base cost of his shares from £50,000 to £20,000.

This means the CGT is generally deferred until a later disposal of the shares, rather than disappearing altogether.

What if you receive cash as well as shares?

This is where the calculation becomes particularly important.

If part of the consideration received for the business is cash and the remainder is shares, Incorporation Relief generally applies only to the part of the gain attributable to the shares.

For example, suppose:

• Business value: £50,000
• Shares received: £40,000
• Cash received: £10,000
• Capital gain: £30,000

The proportion represented by shares is:

£40,000 ÷ £50,000 = 80%

Therefore, the gain eligible for deferral would be:

£30,000 × 80% = £24,000

The remaining £6,000 attributable to the cash would generally be immediately chargeable, subject to the normal CGT rules and any other available reliefs or exemptions. HMRC gives the same principle in its guidance on part-share, part-cash consideration.

The important change from 6 April 2026

This is the part business owners should not overlook.

For transfers taking place before 6 April 2026, Incorporation Relief was generally automatic when the statutory conditions were satisfied, although taxpayers could elect for the relief not to apply.

For transfers taking place on or after 6 April 2026, a claim is required.

HMRC states that the claim is normally made through the Self Assessment tax return for the tax year in which the transfer takes place. The claim must be made by the first anniversary of 31 January following the tax year of the transfer.

Example of the new deadline

Suppose a sole trader transfers their business to a limited company on 19 July 2026.

This falls within the 2026/27 tax year.

The normal Self Assessment filing date is 31 January 2028. The Incorporation Relief claim deadline is therefore 31 January 2029. HMRC confirms this example in its current Capital Gains Tax Manual.

So, if you incorporated your business on or after 6 April 2026, don’t assume the relief will simply be applied automatically.

Is Incorporation Relief always beneficial?

Not necessarily.

Deferring a gain is not the same as eliminating it. The deferred gain generally reduces the base cost of the shares, which can increase the taxable gain when those shares are eventually disposed of.

There may also be circumstances where claiming the relief does not produce the outcome you expect. For example, the overall tax position may be affected by capital losses, available exemptions or other reliefs.

This is why the incorporation transaction should be reviewed as a whole rather than treating Incorporation Relief as an automatic “tax saving”.

What should business owners check?

If you are planning to incorporate your sole trader or partnership business, consider:

• Whether the business meets the conditions for Incorporation Relief
• Which business assets are being transferred
• The market value of the assets at the date of transfer
• Whether consideration is being received in shares, cash or both
• The capital gain arising on the transfer
• The impact of reducing the base cost of the shares
• Whether other capital losses or reliefs affect the position
• Whether a claim is required under the rules applying from 6 April 2026
• The deadline for making the claim

Getting the calculation and paperwork right at the time of incorporation can help avoid an unexpected CGT problem later.

Final thought

Incorporating a business is more than simply setting up a limited company with Companies House. The transfer of the existing business and its assets can have important Capital Gains Tax consequences.

Incorporation Relief may allow qualifying gains to be deferred, but for transfers from 6 April 2026 onwards, remember that a claim is required.

If you are considering moving from sole trader to limited company, it is worth reviewing the tax position before completing the transfer.

This article provides general information and should not be treated as personalised tax advice. The availability and calculation of Incorporation Relief depend on the facts and circumstances of each case.