Does the 18% rate change?

No. The Budget announced a change to the lifetime limit, not the rate. Qualifying gains within the limit are still taxed at 18%, and the Budget announced no change to the main Capital Gains Tax rates of 18% and 24%.

Will the new Founders' Relief help?

Probably not for most owner-managed security firms, in our view. It offers 10% on up to £10 million of lifetime gains from April 2027, but it is under consultation and the proposed conditions include a 25% holding from the start of trading, at least £10 million of turnover and at least 15 full-time equivalent employees.

The Relief Limit Falls to £500,000: What It Means for Security Owners

Q: If I sign a contract before April 2027, do I keep the £1 million limit?

Not simply. Specific rules will apply to unconditional contracts signed before the change and completed after it. The £500,000 limit applies unless the parties can show the contract was not entered into for a tax advantage from the timing. Take advice on your own deal.

What the Budget announced

A security business owner thinking about a sale has a new date in the diary. Here is what it does, and what it leaves alone.

The October 2026 Budget announced that the Business Asset Disposal Relief lifetime limit will fall from £1 million to £500,000 for qualifying disposals from the start of the 2027 to 2028 tax year in April 2027 (HMRC). The 18% rate does not change, and the Budget announced no change to the main Capital Gains Tax rates of 18% and 24%. Legislation is due in Finance Bill 2026-27.

It is a lifetime limit and it takes account of relief already claimed on past gains. So an owner who has already used £500,000 or more would have none left for a disposal after the change.

HMRC estimates that about 75% of roughly 51,000 claimants are unaffected and that about 13,000 individuals are affected. If your gain is likely to be under £500,000, the change may make no difference to you.

What it means in money

For a higher rate taxpayer the relief is worth six percentage points, the gap between 18% and 24%. That is at most £60,000 on a gain of £1 million and at most £30,000 on a gain of £500,000.

Three examples, for a higher rate taxpayer who has claimed no relief before. They leave out the annual exempt amount, costs and any unused basic rate band.

A gain of £400,000: £72,000 of tax under either limit.
A gain of £800,000: £144,000 under the £1 million limit and £162,000 under the £500,000 limit, which is £18,000 more.
A gain of £1.5 million: £300,000 under the £1 million limit and £330,000 under the £500,000 limit, which is £30,000 more.

What the date does and does not mean

A sale takes months and may not complete by April 2027, so this is no reason to rush, and nobody can promise a date. If a sale in the next year or two was already on your mind, you now have a dated reason to find out what the business is worth and how long a sale would take.

The date that counts for tax is normally the date of an unconditional contract, not completion. Specific rules will apply to unconditional contracts signed before the change and completed after it: the £500,000 limit applies unless the parties can show the contract was not entered into for a tax advantage from the timing, and connected parties will also need to show it was entered into for wholly commercial reasons. Signing early is not a simple way to keep the old limit. Take advice from your tax adviser early.

Alarm lines and licences

For alarm and monitoring firms, another date falls first. Analogue landlines are due to close in January 2027 (Openreach), and government guidance names burglar alarms among the devices that may use them (GOV.UK). In our view a customer base already moved to digital signalling is a cleaner thing to buy.

Licensing is the other thing to have straight. Individual SIA licensing is a legal requirement, including for directors of firms supplying operatives, while the Approved Contractor Scheme is voluntary. How you present both is part of how a buyer reads the business, whichever year you decide to sell.

Start From a Real Number

Knowing roughly what the business is worth tells you whether the limit touches you at all. The valuation is private, quick, and lists nothing.

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Before a sale you will need an accountant or tax adviser and a corporate solicitor, and it helps to know when to bring each one in.