Welcome to Capital Gains Tax (CGT)!
Hello there! If you’ve ever sold something for more than you paid for it—like a rare comic book, some shares, or an investment property—you’ve made a "gain." Capital Gains Tax (CGT) is simply the tax the government collects on that profit. Don't worry if tax sounds intimidating; at its heart, CGT is just a bit of subtraction and then applying a percentage. In this chapter, we will learn exactly how to calculate that gain and work out how much tax is owed to HMRC.
1. The Golden Rule: The Basic Formula
Before we dive into the details, let's look at the "Big Picture." Calculating a capital gain is like checking your profit on a side hustle. You take what you sold it for and take away what it cost you.
The Basic Computation:
Disposal Proceeds (What you sold it for)
Less: Incidental costs of disposal (Selling costs like legal fees or advertising)
= Net Disposal Proceeds
Less: Allowable costs (What you originally paid + buying costs + improvements)
= Chargeable Gain / (Loss)
Example: Imagine you bought a painting for £10,000 and paid £500 in auction fees. Years later, you sell it for £20,000 but have to pay a £1,000 commission to the gallery. Your gain is £20,000 (Sold) - £1,000 (Gallery fee) - £10,500 (Total original cost) = £8,500.
Quick Review: What are "Allowable Costs"?
1. Acquisition Cost: The price you paid for the asset.
2. Incidental Costs of Purchase: Stamp duty, legal fees, or surveyor fees paid when you bought it.
3. Enhancement Expenditure: Money spent that adds value to the asset (like building a conservatory on a house). Important: Normal repairs (like painting a wall or fixing a leaky roof) are not allowed here because they just maintain the value, they don't "enhance" it.
Summary: CGT is only charged on the profit (the gain), not the total amount of money you receive.
2. The Annual Exempt Amount (AEA)
Did you know that every individual gets a "tax-free slice" of gains every year? This is called the Annual Exempt Amount (AEA). For the 2025-26 tax year, the AEA is £3,000. Think of it like the Personal Allowance for your income, but specifically for your capital gains.
Key Rules for the AEA:
- It is a fixed amount set for the tax year (£3,000).
- If you don’t use it, you lose it! You cannot carry it forward to next year.
- It is deducted from your total net chargeable gains for the year to find your Taxable Gain.
\( \text{Total Chargeable Gains} - \text{Annual Exempt Amount (AEA)} = \text{Taxable Gains} \)
Common Mistake to Avoid: Don't try to use the AEA to create a loss. If your gain is £2,000 and the AEA is £3,000, your taxable gain just becomes zero. You don't get a £1,000 "bonus" loss to carry forward or use elsewhere!
3. Dealing with Capital Losses
Sometimes, investments go down in value. If you sell an asset for less than it cost you, you have a Capital Loss. The tax rules allow you to use these losses to reduce your gains.
How to use losses:
1. Current Year Losses: Must be set against Current Year Gains first (before deducting the AEA).
2. Brought Forward Losses: If you still have taxable gains left after using current year losses and the AEA, you can use losses from previous years to reduce gains down to the AEA.
3. Memory Aid: Use the "C-A-B" rule: Current year losses first, then AEA, then Brought forward losses.
Key Takeaway: Losses help lower your taxable gains and reduce your tax bill!
4. Calculating the Tax: The Rates
Now for the part everyone wants to know: "How much tax do I actually pay?" Under Finance Act 2025, the rates of CGT are 18% and 24%. The rate you pay depends on your income tax band.
Step 1: Check your Income Tax Band
We look at your Taxable Income first to see how much of your Basic Rate Band (£37,700) is still available.
Step 2: Apply the Rates
- Lower Rate (18%): If your taxable gain fits into your unused basic rate band, it is taxed at the lower rate of 18%.
- Higher Rate (24%): Any taxable gain that exceeds your unused basic rate band falls into the higher rate band and is taxed at 24%.
Analogy: Imagine your Basic Rate Band is a bucket of £37,700. Your taxable income goes in first. If the bucket isn't full, your capital gains go in next and are taxed at the lower rate of 18%. Once that bucket is full, any leftover gains spill into the higher tier and are taxed at 24%.
5. Reporting and Paying CGT
For most assets, you report your gains on your annual Self-Assessment tax return. However, there is a special rule for disposals of UK Residential Property.
The 60-Day Rule: If you sell a UK residential property and have capital gains tax to pay, you must submit a residential property CGT return and pay the tax to HMRC within 60 days of completion.
Summary: General gains follow the normal self-assessment tax return cycle, but residential property disposals with tax payable have a 60-day reporting and payment deadline.
Final Checklist for Success
When you are sitting in your exam and see a CGT question, follow these steps:
1. Calculate the Gain: (Net disposal proceeds - Allowable costs).
2. Apply Losses: Deduct current year capital losses.
3. Deduct the AEA: Deduct the £3,000 annual exempt amount.
4. Find the Unused Basic Rate Band: Check how much of the £37,700 basic rate band remains after taxable income.
5. Calculate Tax: Multiply gains falling within the unused basic rate band by 18% and any remaining gains by 24%.
Don't worry if this seems tricky at first! The more you practice the standard computation layout, the more natural it will become. You've got this!