Capital Gains Tax for Investors

CGT generally applies when you dispose of a chargeable asset and make a gain. Common examples:

• Shares and funds (including ETFs and investment trusts)
• Cryptoassets (e.g., Bitcoin, Ethereum)
• Second homes or buy-to-let property (your main residence may qualify for relief)
• Business assets in some circumstances

Disposal usually means a sale, but it can include gifts (other than to a spouse/civil partner), part-sales, or exchanging one asset for another. You’ll compare what you received (or the asset’s market value in certain cases) with what the asset cost you, including allowable costs such as broker fees, stamp duty, and certain improvement costs for property.

Dividends and bank interest aren’t capital gains, report them on the SA100 (and SA106 if they’re foreign-source). Gains go on SA108.

For most disposals the basic CGT calculation is:

Proceeds – (Purchase cost + Allowable purchase costs + Allowable selling costs) – Available losses = Gain

A few pointers:

• Shares and funds: HMRC’s share pooling rules normally apply; track total pooled cost and units. Corporate actions (splits, consolidations) adjust your pool.
• Crypto: Treat each token as an asset; pooling rules can also apply. Keep clear records of dates, quantities, and fees.
• Property: Include legal fees, agent fees, and allowable enhancement costs in your base cost (not routine repairs). If it was ever your main home, consider whether any relief could apply.

If you’ve made capital losses, you can set them against gains in the same year; unused losses can usually be carried forward once claimed.

Ftax’s SA108 workflow lets you enter each disposal cleanly, applies the right computations, and produces a clear summary you can keep with your records.

Further information can be found here on the HMRC website.

• Dividends & savings interest: Enter on the SA100 (add SA106 for foreign dividends/interest). Keep platform/bank summaries.
• Capital gains: Add the SA108 pages. You’ll summarise total proceeds, costs, gains/losses, and claim any brought-forward losses where eligible.
• Foreign investments: Use SA106 for foreign income; gains on overseas assets still go on SA108. You may be able to claim foreign tax credit relief where a treaty allows.

• Self Assessment online filing: file by 31 January following the end of the tax year.
• Payment: usually due by 31 January (and 31 July if Payments on Account apply; note these typically relate to income tax rather than CGT).
• UK residential property gains: many disposals require a separate UK property CGT return and payment on account within a short time after completion (in addition to year-end Self Assessment). Check the current HMRC rules for your disposal type.

Filing early with Ftax confirms your bill in good time, helps you plan cash flow, and avoids the January rush.

Several rules can reduce your investor tax bill. The specifics change over time, so use the current tax year’s thresholds and conditions:

• Annual CGT allowance (exemption): a tax-free slice of gains each year.
• Utilising losses: current-year and brought-forward losses can reduce gains.
• Main residence and other property reliefs: where conditions are met.
• Dividend allowance & rates: dividends are taxed separately from gains; report them on SA100 (and SA106 if foreign).
• Interest allowances: savings interest may be covered in part by the Personal Savings Allowance or starting rate for savings, depending on your circumstances.

Ftax helps you enter the right figures once and see the impact immediately in your calculation.