Who operates FiscalFox
FiscalFox is developed and operated by Rolling Sloane Technology Limited, a company registered in England and Wales under company number 16659202. Its registered office is 124 City Road, London EC1V 2NX.
The product is designed to turn supported broker exports into transparent UK capital gains calculations. It shows transaction data, disposal-level workings and the share-matching treatment used, so the result can be reviewed before it is used in a tax return.
Editorial accountability
Grant Christopher Sloane, a director and the product lead for FiscalFox, is accountable for the calculator's published methodology, product-limit disclosures and editorial correction process. His directorship is listed on the public Companies House record.
This attribution identifies who owns the publication process; it is not a claim that FiscalFox or its director provides regulated personal tax advice. Where a user's facts involve employee share schemes, residence, remittance, trusts, reorganisations or another specialist issue, the relevant calculation should be checked by a suitably qualified tax adviser.
Our tax-content standard
Tax guides are checked against current GOV.UK pages, HMRC Self Assessment helpsheets and the HMRC Capital Gains Manual. Each dated guide displays when it was last updated and links to the relevant official material. We update rate, allowance and filing content when published rules change, and avoid presenting an estimate as an HMRC submission or personal tax advice.
- Primary sources are preferred over summaries from third-party publishers.
- Worked examples state their assumptions and do not substitute for a user's full facts.
- Material product limitations and transactions requiring manual review are disclosed.
- Calculation outputs retain the underlying matching workings for review.
Editorial checks and calculation-engine tests serve different purposes. The editorial process confirms that published rates, allowances, filing boundaries and linked guidance reflect the cited primary source. Automated tests check deterministic importer and matching behaviour. Neither process can establish that a user's broker history is complete, so warnings and reconciliation steps remain part of the output.
What FiscalFox does and does not do
FiscalFox applies supported UK share-matching logic and prepares calculation reports that can support the SA108 Capital Gains summary. It does not file a return with HMRC, guarantee that an incomplete broker export is complete, or provide regulated personal tax advice. Corporate actions, employee share schemes, unidentified instruments and unusual residency or remittance circumstances may need additional evidence and professional review.
Corrections and questions
If you spot a source that has changed or believe a guide needs clarification, contact the FiscalFox support team through the support page. We review corrections against primary evidence and update the affected page where appropriate.