If you are selling a business, shares, or an investment property, you will likely owe Capital Gains Tax (CGT) on the profit. The rules are not simple. Rates changed in 2024 and again in 2025. Reliefs like Business Asset Disposal Relief (BADR) now have a 14% rate, rising to 18% from April 2026. Getting the calculation wrong can cost you thousands. That is when you need a cgt accountant uk to handle the numbers and the paperwork.
This article covers exactly when you should hire a CGT specialist, what they do, and how to avoid the common mistakes that trigger HMRC enquiries.
What Does a CGT Accountant UK Actually Do?
A CGT accountant does not just fill in a tax return. They work through the full disposal process from start to finish. That means calculating the chargeable gain correctly, identifying every relief you qualify for, and making sure the right forms reach HMRC on time.
The key tasks include:
- Calculating the base cost of the asset, including acquisition costs, enhancement expenditure, and indexation allowance (for corporate disposals before December 2017).
- Identifying reliefs such as BADR, Entrepreneurs' Relief (pre-2020), Investors' Relief, holdover relief, gift relief, and principal private residence relief.
- Planning the timing of the disposal to optimise the tax year and the rate you pay.
- Filing the right returns including the 60-day CGT property return for UK residential property, the self assessment return (SA100 or SA108), and the company's corporation tax return (CT600) if the asset is held in a limited company.
- Handling HMRC enquiries if your return is selected for review.
As ICAEW qualified accountants, we see clients who have tried to handle CGT themselves and ended up overpaying by 10% or more because they missed a relief or miscalculated the gain. A specialist fixes that.
When Do You Need a CGT Accountant? Five Scenarios
1. Selling Your Limited Company Shares
If you own shares in your own limited company and sell them, the gain is subject to CGT. The rate depends on your total income and gains for the year. For disposals from 6 April 2025, the BADR rate is 14% on the first £1 million of qualifying gains. Above that, you pay 18% (basic rate) or 24% (higher rate).
To qualify for BADR, you must meet specific conditions. You need to have been an officer or employee of the company for at least two years before the disposal. The company must be a trading company (not an investment company). And the shares must represent at least 5% of the ordinary share capital and voting rights.
A cgt accountant uk checks every condition. If you miss one, you lose the relief and pay the full rate. That is a difference of 10% on a £500,000 gain: £50,000 extra tax.
2. Selling a Buy-to-Let or Second Home
UK residential property gains are taxed at 18% (basic rate) or 24% (higher rate). You must report the gain to HMRC within 60 days of completion using the CGT property return. Miss that deadline and you face penalties starting at £100 and rising to 10% of the tax due if you are more than 12 months late.
A CGT accountant ensures the gain is calculated correctly, including allowable costs like stamp duty, legal fees, and improvement costs. They also check whether principal private residence relief applies if you lived in the property at any point.
If you are selling a property that was your main home for part of the ownership period, the relief can be significant. The final 9 months of ownership are always exempt. A specialist works through the numbers to get it right.
3. Selling a Business as a Sole Trader or Partnership
Sole traders and partnerships do not pay corporation tax on asset sales. They pay CGT on the gain from selling goodwill, premises, or equipment. BADR applies here too, provided you have owned the business for at least two years.
The calculation is more complex than for shares because you need to allocate the sale price across different assets. Goodwill is often the largest element. HMRC scrutinises goodwill valuations closely. If your valuation is not supported by a professional report, you risk an enquiry.
A cgt accountant uk works with your solicitor or a valuation specialist to document the basis for the goodwill figure. That documentation is your defence if HMRC challenges the return.
4. Gifting Assets to Family Members
Gifting an asset to a spouse or civil partner is generally exempt from CGT. But gifting to a child, sibling, or other family member is a disposal at market value. You owe CGT on the gain even though no cash changes hands.
Holdover relief can defer the gain until the recipient sells the asset. But the rules are tight. The recipient must be UK resident and the asset must be a business asset or certain types of shares. A CGT specialist structures the gift to avoid an immediate tax bill where possible.
5. Selling Shares in an EIS or SEIS Company
Shares in Enterprise Investment Scheme (EIS) or Seed Enterprise Investment Scheme (SEIS) companies can be exempt from CGT if held for the required period. But the conditions are strict. You must have received the relevant compliance certificates and held the shares for at least three years (EIS) or three years (SEIS).
If you sell before the holding period ends, the gain is taxable. A cgt accountant uk reviews your share certificates, the company's compliance status, and the disposal date to confirm whether the exemption applies.
How a CGT Accountant Saves You Money
The obvious saving is getting the reliefs right. But there are other ways a specialist adds value.
Annual exempt amount. For 2025/26, the CGT annual exempt amount is £3,000. If your total gains for the year are below that, no tax is due. A CGT accountant plans disposals across tax years to maximise the use of this allowance.
Spouse and civil partner transfers. You can transfer assets to your spouse or civil partner without triggering a CGT charge. This allows you to use both annual exempt amounts. A specialist structures the transfer before the sale to double the allowance.
Loss relief. If you have capital losses from previous years or current year disposals, they can be offset against gains. A CGT accountant tracks losses and ensures they are used in the most tax-efficient order.
Incorporation relief. If you are a sole trader or partnership selling to a limited company you control, incorporation relief can defer the gain. The relief applies automatically if the conditions are met. A specialist ensures the paperwork is in place to claim it.
What Happens If You Get It Wrong?
HMRC has a team dedicated to CGT compliance. They review returns for unusual patterns, missing reliefs, and undervalued assets. If they open an enquiry, you need to provide evidence for every figure on the return.
Common triggers for an HMRC enquiry include:
- Claiming BADR without meeting the trading company test.
- Valuing goodwill or shares at a low figure without supporting evidence.
- Reporting a gain on a property sale late (beyond the 60-day window).
- Claiming principal private residence relief for a property that was not your main home.
If HMRC challenges your return and you cannot justify the figures, you face the full tax plus interest and penalties. Penalties for careless inaccuracies start at 15% of the extra tax due. For deliberate inaccuracies, they go up to 100%.
A cgt accountant uk builds the evidence file at the time of disposal. That means you are ready for an enquiry from day one.
How to Choose a CGT Accountant
Not every accountant handles CGT well. Some focus on compliance and do not have the experience to plan complex disposals. Here is what to look for.
- ICAEW or ACCA qualification. This is a minimum. It means the accountant has passed rigorous exams and follows a professional code of conduct.
- Specific CGT experience. Ask how many disposal transactions they have handled in the last 12 months. If the answer is vague, keep looking.
- Knowledge of your asset type. Selling a limited company is different from selling a buy-to-let. The reliefs, forms, and deadlines differ. Make sure the accountant has handled your type of disposal before.
- Proactive planning. A good CGT accountant does not wait for the sale to happen. They review your situation in advance and suggest timing, structuring, and relief strategies.
Our ICAEW qualified team works with business owners across the UK, from a tech founder in Shoreditch selling their SaaS company to a landlord in Birmingham selling a portfolio of buy-to-lets. We handle the full disposal process from planning to filing.
What Does a CGT Accountant Cost?
Fees vary depending on the complexity of the disposal. A straightforward share sale with a clear BADR claim might cost between £500 and £1,500 for the CGT return and planning work. A complex disposal involving multiple assets, valuations, and reliefs can cost £2,000 to £5,000 or more.
Compare that to the tax saving. If a CGT accountant saves you £50,000 by correctly claiming BADR, the fee is a fraction of the benefit. The return on investment is clear.
Some accountants charge a fixed fee for the work. Others charge by the hour. We typically offer a fixed fee for CGT work so you know the cost upfront. Contact us for a quote based on your specific situation.
When to Start the Process
Start planning before you exchange contracts. That gives you time to:
- Review the reliefs available.
- Structure the sale to minimise tax.
- Get valuations done.
- Prepare the documentation.
If you have already exchanged contracts, you can still get help with the calculation and filing. But you lose the opportunity to plan the timing and structure.
The best time to speak to a cgt accountant uk is three to six months before you expect to sell. If you are thinking about selling in the next 12 months, book a consultation now.