The FRC taxonomy is the official UK digital reporting taxonomy used to tag accounts and related reports in iXBRL. It gives software a structured list of accounting concepts so HMRC, Companies House and reviewers can process tagged accounts consistently.
This guide is source-linked to official HMRC, Companies House and FRC material where available. Check current official guidance before treating the filing route, deadline or taxonomy choice as final.
What the taxonomy does
The taxonomy is a structured dictionary of reporting concepts. Instead of tagging a number only as visible text, the preparer links it to a concept such as turnover, trade creditors or profit after tax.
- It supports machine-readable accounts.
- It helps validation and downstream review.
- It should reflect accounting meaning, not visual layout only.
Where it fits in UK filing
For UK company tax and accounts workflows, the FRC taxonomy supports iXBRL tagging of accounts and related reports. HMRC CT600 filing and Companies House accounts filing remain separate routes, but both can depend on correctly prepared accounts.
- HMRC route: CT600, computations and tagged accounts where required.
- Companies House route: statutory accounts and accounts filing evidence.
- Taxonomy choice should be recorded with the filing pack.
What reviewers should check
Reviewers should test whether the chosen tags match the accounting substance of the source accounts and whether any software-created extensions are necessary and controlled.
- Review material line items and disclosures.
- Check unusual tags and extension concepts.
- Revalidate after taxonomy or account changes.
Common risks
Common risks include treating HMRC and Companies House as one combined filing, using an old taxonomy assumption, copying prior-year tags without review, ignoring validation warnings, missing separate deadlines and losing evidence of approval.
- Do not rely only on prior-year files.
- Do not treat validation as a substitute for accounting or tax review.
- Escalate unusual balances, late filings or regulator-specific issues early.
Evidence to retain
The filing record should show the source accounts used, the HMRC or Companies House route decision, mapping or tagging review, validation results, corrections, approvals and final filing confirmation.
- Save signed or approved accounts and version details.
- Save validation and correction evidence for iXBRL files.
- Save HMRC, Companies House, upload or adviser handoff confirmation.
Before you rely on this route
- Applicable FRC taxonomy identified.
- Accounts framework confirmed.
- Material tags reviewed for accounting meaning.
- Extensions reviewed and justified.
- Validation evidence saved.
Official sources
Use these official references as the current regulatory baseline before making filing decisions.
FAQs
What is the short answer?
UK iXBRL tagging should use the applicable FRC taxonomy and accounting meaning from the source accounts. Teams should avoid label-only matching, validate the tagged file, and retain review evidence before HMRC or Companies House submission.
Are HMRC and Companies House filings the same?
No. Companies House accounts filing and HMRC Company Tax Return filing are separate UK obligations, even where the same statutory accounts support both workflows.
Can prior-year iXBRL files be reused?
Prior-year files can be a reference, but the current company facts, accounts, taxonomy, validation rules and official filing route should be checked again.
When should professional review be used?
Use professional review when the route is unclear, the filing is late, source documents changed, CT600 or tax computations changed, or the entity has unusual disclosures.
This article is general UK iXBRL filing information, not legal, tax, accounting or regulatory advice. Check current HMRC, Companies House and FRC guidance, and seek professional advice before making filing decisions.