Sharesight UK CGT: FiscalFox vs Sharesight

Short answer: Sharesight is the stronger choice for ongoing portfolio performance and investment-income tracking. FiscalFox is the more relevant choice when the specific job is calculating UK Capital Gains Tax on shares. As of 17 August 2026, Sharesight's UK help centre says it does not offer a UK CGT report or support the UK 30-day rule; FiscalFox applies same-day, following-30-day and Section 104 matching to supported broker data.

This is not a claim that Sharesight is inaccurate or unsuitable generally. The products solve different problems. Sharesight is an established portfolio tracker with broad market and broker coverage. FiscalFox is a specialist UK tax calculation workflow designed to turn transaction exports into checkable disposal workings and Self Assessment supporting reports.

FiscalFox vs Sharesight for UK investors

Sources checked on 17 August 2026: the Sharesight UK CGT help page (shown as last updated 17 July 2026), Sharesight's UK investment tax-reporting page, and HMRC Helpsheet 284. Product capabilities and prices can change, so follow the dated source links before making a decision.

Does Sharesight calculate UK Capital Gains Tax?

Not as a UK CGT report at the time of this review. Sharesight's UK help centre says that it does not currently provide one and names the 30-day rule as an unsupported UK-specific rule. It instead recommends that investors consult a UK tax adviser or accountant for capital gains calculations.

That limitation is narrower than “Sharesight does not help with tax”. Its UK product page describes a Taxable Income Report, a sold-securities report using average cost, trade-history exports and accountant sharing. Those features can be useful inputs to a tax workflow, but average-cost realised gains alone are not the same as a calculation applying the full UK share-identification sequence.

Why the 30-day rule and Section 104 holding matter

For UK CGT, the allowable cost of a disposal depends on which acquisitions HMRC treats as the shares sold. HMRC's published order is the practical dividing line in this comparison:

1. Same day: match acquisitions of the same shares made on the disposal date.
2. Following 30 days: match remaining disposals with acquisitions in the next 30 days, in date order.
3. Section 104 holding: match any remainder against the pooled holding and its average allowable cost.

A repurchase after a sale can therefore change the gain or loss on that earlier disposal. The broker account in which the trade occurred does not remove the need to consider the same beneficial owner's other taxable accounts. Read the detailed guides to the same-day rule, 30-day rule and Section 104 pools.

Which product should you choose?

Choose Sharesight for portfolio tracking

Sharesight is the better fit if your main goal is to monitor investment performance, consolidate holdings, track dividends and distributions, or share a portfolio view with an adviser. Its broker coverage and long-running market-data history are materially broader than FiscalFox's specialist import list.

Choose FiscalFox for a UK CGT calculation

FiscalFox is the better fit if you need to import supported broker histories, combine matching securities across taxable accounts, apply the UK matching order and inspect how each disposal was calculated. You can review the calculation free before deciding whether to buy the £29.99 report pack for a selected tax year.

Use both when the jobs are separate

The tools do not have to be substitutes. A sensible workflow is to use Sharesight for ongoing portfolio visibility and FiscalFox for the year-end UK CGT calculation. FiscalFox does not currently import data directly from Sharesight, so use complete broker transaction exports and reconcile the holdings before relying on the result.

What the FiscalFox UK CGT workflow includes

1. Import: upload one or more supported broker CSV or Excel files.
2. Combine: bring the same securities together across taxable accounts before matching.
3. Calculate: apply same-day, following-30-day and Section 104 matching in sequence.
4. Review: inspect warnings, disposal computations and pool workings before using the totals.
5. Export if needed: unlock PDF and CSV reports for one tax year with a £29.99 one-off payment.

Start with the free UK CGT calculation, inspect the FiscalFox methodology, or open the synthetic sample report before paying.

Limitations to check before relying on either tool

FiscalFox is not a complete portfolio tracker and is not a crypto CGT calculator. Brought-forward capital losses are not currently entered or applied automatically. Incomplete history, stock reorganisations, employee-share events, missing foreign-exchange evidence and ambiguous securities can require manual review or professional advice.

Sharesight's current limitation is different: it offers useful portfolio and income-tax reporting, but its UK help centre says it does not currently provide the UK CGT report covered by this comparison. If Sharesight adds UK CGT and 30-day matching later, this page will need to be reassessed against the new implementation.

Verdict: FiscalFox for UK CGT, Sharesight for tracking

If your search is specifically “Sharesight UK CGT” or “Sharesight alternative for UK tax”, FiscalFox is the closer match for the calculation task: it applies the UK share-matching sequence, accepts supported broker exports and keeps the workings visible. If your priority is portfolio performance, holdings and income monitoring, Sharesight is the broader product.

FiscalFox is independent and is not affiliated with, endorsed by or sponsored by Sharesight. Sharesight is a trademark of its respective owner. This comparison concerns the products' publicly documented UK functionality on the review date and does not constitute tax, financial or product advice.