GainPool — macOS & Windows

Broker exports in.
Capital Gains worked out.

HMRC's matching order applied in full, Section 104 pools with their whole history shown, the tax actually due, SA108 figures, and a computation pack your accountant will nod at.

GainPool's Section 104 pool timelines: for each security, every acquisition and disposal with the change in quantity and cost, and the running pool quantity and cost after each event.

Section 104 pool timeline — running quantity and cost after every event

What you end up with

SA108 figures

The boxes as they appear on the Capital Gains summary, ready to copy onto your return.

Computation pack

Every matched slice and pool movement behind each figure, as PDF and CSV.

Disposals CSV

The full disposal list, for your own records or your accountant's software.

Encrypted session

Your normalised transactions saved locally, so next year you reload instead of re-importing.

Broker support

Profiles marked beta work, but have not yet been validated against a real customer export.

Trading 212Validated
FreetradeBeta
Hargreaves LansdownBeta
AJ BellBeta
interactive investorBeta
Vanguard UKBeta
DEGIROBeta
Interactive BrokersBeta
CoinbaseBeta

Broker not listed? The column-mapping wizard walks through an unrecognised CSV once and saves it as a new platform.

Reads real broker exports

Trading 212 first-class; Freetrade, Hargreaves Lansdown, AJ Bell, interactive investor, Vanguard UK, DEGIRO, Interactive Brokers and Coinbase via built-in profiles; anything else through a column-mapping wizard that can save itself as a new platform.

Applies the rules, not an approximation

Same-day, then bed-and-breakfast (30-day), then the Section 104 average-cost pool. Money is decimal throughout — never floating point.

Knows what's exempt

ISA and SIPP exports are recognised and excluded from CGT rather than silently pooled with taxable accounts.

Handles the awkward parts

Foreign-currency-priced but GBP-settled trades, manual adjustments, the 30 October 2024 rate change, and the capital-loss ledger with its four-year claim deadline.

Looks forward, not just back

Remaining Annual Exempt Amount headroom, unrealised gains, and 30-day-rule warnings before you sell.

Saves your work

Sessions persist the normalised transaction stream encrypted at rest, so you reload instead of re-importing.

The matching order

A

Same day

Disposals match acquisitions made on the same date first.

B

Next 30 days

Then acquisitions in the following thirty days — the bed-and-breakfast rule.

C

Section 104 pool

Whatever remains comes from the average-cost pool, with its history shown.

Covered

  • UK-resident individuals
  • Listed shares, funds, supported crypto
  • Taxable accounts, with ISA/SIPP excluded
  • 2020/21 – 2025/26 filing, 2026/27 planning

Not covered

  • Property, trusts and companies
  • Non-resident computations
  • Sophisticated reliefs
  • Filing to HMRC on your behalf

Test it against your real exports.

We're looking for people who file their own Capital Gains and will run an early build alongside their existing calculation.