Companies House filing is about statutory accounts, while HMRC Company Tax Return filing is about Corporation Tax, CT600, computations and iXBRL-tagged accounts where required. The deadlines are different, so one filing route should not be assumed to complete the other.
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.
Direct answer
HMRC CT600 filing and Companies House accounts filing are separate UK workflows. Companies House filing deals with statutory accounts. HMRC filing deals with the Company Tax Return, Corporation Tax, computations and iXBRL-tagged accounts where required.
- Do not assume one confirmation completes both obligations.
- Check each deadline separately.
- Keep separate submission evidence.
HMRC CT600 workflow
The HMRC workflow starts from the Company Tax Return obligation. It normally includes the CT600, Corporation Tax calculation, tax computations and accounts evidence, with iXBRL tagging and validation where required by the filing process.
- Confirm the HMRC notice to deliver.
- Prepare CT600 and computations from final numbers.
- Validate and retain the HMRC submission pack.
Companies House workflow
The Companies House workflow starts from statutory accounts. The accounts should be prepared from company records, approved as required, and filed by the Companies House deadline.
- Confirm accounts filing deadline.
- Confirm accounts type: full, abridged, micro-entity, dormant or other route.
- Retain filing confirmation and submitted accounts version.
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
- HMRC CT600 status checked.
- Companies House accounts deadline checked.
- Accounts source version reconciled.
- Tax computation source version reconciled.
- Two filing confirmations retained where both apply.
Official sources
Use these official references as the current regulatory baseline before making filing decisions.
FAQs
What is the short answer?
Companies House filing is about statutory accounts, while HMRC Company Tax Return filing is about Corporation Tax, CT600, computations and iXBRL-tagged accounts where required. The deadlines are different, so one filing route should not be assumed to complete the other.
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.