Methodology
Sterling source universe
Every reviewed source family, its authority and its permitted use.
Sterling records source-family policy separately from individual documents. This makes acquisition, storage, derivation, public exposure and monitoring decisions reviewable without flattening each source's own structure.
Acquisition routes · Sources and authority · Research and review
Last reviewed 11 September 2026
Primary authority
- UK legislation — Official API; Attributed derived content.
- Finance Bills and parliamentary bill material — Official feed; Attributed derived content.
- Scottish Parliament tax resolutions — Link and cite only; Attributed derived content.
- Senedd tax resolutions — Link and cite only; Metadata and citation only.
- Official tax tribunals and courts — Permitted automated ingestion; Attributed derived content.
- FRC accounting standards — Link and cite only; Metadata and citation only.
Official interpretation
- Scottish Government tax guidance — Link and cite only; Attributed derived content.
- GOV.UK tax and business guidance — Official API; Attributed derived content.
- HMRC manuals — Official API; Attributed derived content.
- Revenue and Customs Briefs and HMRC Spotlights — Official API; Attributed derived content.
- HM Treasury Budgets, TIINs and consultations — Official API; Attributed derived content.
- Explanatory notes and memoranda — Permitted automated ingestion; Attributed derived content.
- Companies House guidance — Official API; Attributed derived content.
- Insolvency Service guidance — Official API; Attributed derived content.
- ACAS employment guidance — Permitted automated ingestion; Attributed derived content.
- The Pensions Regulator guidance — Link and cite only; Metadata and citation only.
- FCA Handbook and instruments — Official API; Attributed derived content.
- PRA Rulebook and instruments — Link and cite only; Metadata and citation only.
- Department for Work and Pensions guidance — Official API; Attributed derived content.
- Valuation Office Agency guidance — Official API; Attributed derived content.
- HM Land Registry guidance — Official API; Attributed derived content.
- UK local-authority guidance and data — Manual research; Metadata and citation only.
Official implementation
- HMRC tax APIs and schemas — Official API; Attributed derived content.
- HMRC payroll software specifications and routines — Official API; Attributed derived content.
- HMRC forms, instructions and filing schemas — Permitted automated ingestion; Attributed derived content.
- Companies House APIs, streams and filing schemas — Official API; Attributed derived content.
- FRC XBRL and iXBRL taxonomies — Official bulk download; Metadata and citation only.
- HMRC structured rates, thresholds, allowances and deadlines — Official API; Attributed derived content.
Professional interpretation
- Chartered Institute of Taxation — Link and cite only; Metadata and citation only.
- Association of Taxation Technicians — Link and cite only; Metadata and citation only.
- Institute of Chartered Accountants in England and Wales — Link and cite only; Metadata and citation only.
- Association of Chartered Certified Accountants — Link and cite only; Metadata and citation only.
- Institute of Chartered Accountants of Scotland — Link and cite only; Metadata and citation only.
- Association of Accounting Technicians — Link and cite only; Metadata and citation only.
- Deloitte UK publications — Link and cite only; Metadata and citation only.
- PwC UK publications — Link and cite only; Metadata and citation only.
- EY UK publications — Link and cite only; Metadata and citation only.
- KPMG UK publications — Link and cite only; Metadata and citation only.
- BDO UK publications — Link and cite only; Metadata and citation only.
- RSM UK publications — Link and cite only; Metadata and citation only.
- Grant Thornton UK publications — Link and cite only; Metadata and citation only.
- Azets publications — Link and cite only; Metadata and citation only.
- Crowe UK publications — Link and cite only; Metadata and citation only.
- MHA publications — Link and cite only; Metadata and citation only.
- PKF Littlejohn publications — Link and cite only; Metadata and citation only.
- Saffery publications — Link and cite only; Metadata and citation only.
- Evelyn Partners publications — Link and cite only; Metadata and citation only.
- AccountingWEB — Link and cite only; Metadata and citation only.
- Taxation Magazine — Link and cite only; Metadata and citation only.
- Other credible practitioner publications — Manual research; Metadata and citation only.
Licensed specialist
- Tolley and LexisNexis — Licensed acquisition; Metadata and citation only.
- Croner-i — Licensed acquisition; Metadata and citation only.
- Bloomsbury Professional — Licensed acquisition; Metadata and citation only.
- CCH and Wolters Kluwer — Licensed acquisition; Metadata and citation only.
- Practical Law — Licensed acquisition; Metadata and citation only.
- Westlaw UK — Licensed acquisition; Metadata and citation only.
- Commercial IFRS content — Licensed acquisition; Metadata and citation only.
- Professional tax, accounting, corporate-finance and CFO books — Licensed acquisition; Metadata and citation only.
Empirical intelligence
- Companies House company, PSC and filing-history data — Official API; Attributed derived content.
- Companies House bulk data and filed XBRL or iXBRL accounts — Official bulk download; Metadata and citation only.
- Public-company reports — Metadata only; Metadata and citation only.
- Office for National Statistics data — Official bulk download; Attributed derived content.
- Bank of England data — Official API; Attributed derived content.
- HMRC statistics and Tax Gap reports — Official bulk download; Attributed derived content.
- Insolvency statistics — Official bulk download; Attributed derived content.
- The Gazette notices and data — Official feed; Attributed derived content.
- British Business Bank research and programmes — Manual research; Metadata and citation only.
- UK Export Finance programmes — Permitted automated ingestion; Attributed derived content.
- Find a Grant — Manual research; Attributed derived content.
- Innovate UK and UKRI programmes and data — Manual research; Metadata and citation only.
- Contracts Finder — Official API; Attributed derived content.
- Find a Tender — Official API; Attributed derived content.
- Academic and industry datasets — Manual research; Metadata and citation only.
Weak signal
- Practitioner forums and accounting communities — Discovery only; Metadata and citation only.
- Reddit — Discovery only; Metadata and citation only.
- MoneySavingExpert — Discovery only; Metadata and citation only.
- Contractor and business forums — Discovery only; Metadata and citation only.
- Blogs and Q&A sites — Discovery only; Metadata and citation only.
- Unlicensed or technically unsuitable web corpora — Prohibited or unsuitable; Metadata and citation only.
Source registry: sterling-source-registry@2026-09-11.5.