UK FRC taxonomies provide the reporting concepts used for UK iXBRL accounts tagging. The correct taxonomy depends on the accounts framework, reporting period, software support and filing route, so taxonomy selection should be documented before validation.
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.
Taxonomy selection
Taxonomy selection should start from the reporting framework and reporting period, then be checked against the tagging software and filing route. A prior-year taxonomy should not be carried forward without review.
- Confirm UK GAAP, IFRS or other applicable framework.
- Check reporting period and current taxonomy support.
- Document the selected taxonomy in the filing pack.
Relationship to HMRC and Companies House
The FRC taxonomy supports tagged accounts used in filing workflows. It does not remove the need to separately manage HMRC CT600 evidence and Companies House accounts evidence.
- HMRC review should reconcile CT600, computations and tagged accounts.
- Companies House review should reconcile statutory accounts and filing confirmation.
- Both routes should reference the same controlled accounts source where applicable.
Common review controls
Good taxonomy control means checking framework, version, material concept mapping, validation messages and any extensions before the tagged file is released.
- Review material tags manually.
- Investigate validation warnings.
- Save taxonomy/version evidence.
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
- Framework checked.
- Taxonomy version checked.
- Software taxonomy support confirmed.
- Material concept mapping reviewed.
- Validation output 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.