What you sell isn't what you gain. And what you gain isn't what you owe.
Your capital gain depends on what you originally paid, your allowable costs and the tax rules that apply to your transactions.
And even once you've calculated your gains, your actual tax liability may be affected by allowable losses, your annual exempt amount and your wider tax circumstances.
Finbooks helps you work out the figures behind your Capital Gains Tax calculation.

Bring every gain and loss into one CGT calculation
Finbooks reconstructs acquisition costs and disposal history across shares, ETFs, bonds and crypto.
It then applies the relevant HMRC rules to calculate your capital gains and allowable losses, with reports and supporting calculations ready for your Self Assessment.

From your transactions to your CGT calculation in three steps
- 1
Connect your investment accounts
Import your transaction history from supported brokers, exchanges and wallets.
- 2
Let Finbooks calculate your gains
Finbooks reconstructs acquisition costs, applies the relevant UK tax rules and calculates your capital gains and allowable losses.
- 3
Get your tax-ready figures
Access your calculated gains and losses, review the supporting calculations and generate the reports you need for Self Assessment.
Calculate your CGT with Finbooks
Finbooks reviews your imported transaction history and identifies recorded sales and exchanges that need to be included in the CGT calculation.
For each disposal, Finbooks records the value received and the transaction costs relevant to the calculation.
Finbooks applies the same-day rule, the 30-day rule and the Section 104 pool where applicable to determine the allowable cost.
Finbooks compares the disposal proceeds with the allowable cost and calculates the capital gain or allowable loss for each disposal.
Finbooks brings the results together across your portfolio and prepares the supporting calculations needed for your Self Assessment.
Got questions? We have answers
You need the full acquisition and disposal history for the investments you sold, including purchase costs, transaction fees and any relevant transfers.
Finbooks can bring together supported transaction histories across shares, ETFs, bonds and crypto so the calculation reflects your portfolio as a whole.
Yes. You can review the imported transaction history and supporting calculations before generating the report for your Self Assessment or tax adviser.


