When is the HMRC corporation tax filing deadline?

Corporation tax returns (CT600) and computations must be filed to HMRC within 12 months of the accounting period end date. Corporation tax payment is due 9 months and 1 day after the accounting period end.

What is the Companies House statutory accounts deadline?

Statutory accounts must be filed to Companies House within 9 months of the accounting period end for private companies and 6 months for public companies. Late filing incurs automatic penalties starting from £100.

When must listed companies file ESEF/UKSEF reports?

Listed companies must file annual financial reports in ESEF/UKSEF format to the FCA within 4 months of the financial year end. Premium listed companies since 2022, Standard listed from January 2026.

What are the penalties for late iXBRL filing?

Companies House penalties range from £100 (up to 1 month late) to £1,500 (over 6 months late). HMRC charges penalty rates of 5% after 30 days, 5% after 6 months, and 5% after 12 months late, plus interest on unpaid tax.

Can iXBRL filing deadlines be extended?

HMRC and Companies House do not typically grant extensions for filing deadlines. Extensions may be considered in exceptional circumstances such as serious illness or system failures, but must be requested before the deadline with supporting evidence.

AI-Powered iXBRL Filing Solutions for UK Businesses

ISO

27001 Security Certified

99.8%

Success First-Time Acceptance

2,500+

Clients Trusted by UK Firms

HMRC

Approved Compliant Provider

HMRC Corporation Tax Deadlines

HM Revenue & Customs operates strict deadlines for corporation tax returns, computations, and payments. Understanding these timelines is crucial for penalty avoidance.

Corporation Tax Return (CT600) Filing Deadline

12 Months

After accounting period end date

The CT600 corporation tax return and accompanying tax computations must be filed in iXBRL format within 12 months of the accounting period end date.

Important Notes:

Deadline is calendar date, not working days
No grace period - penalties apply immediately
Must be filed even if no tax is due
Dormant companies still have filing obligations

Example: Period ending 31 Dec 2024 → Deadline 31 Dec 2025

Corporation Tax Payment Payment Deadline

9 Months 1 Day

After accounting period end date

Corporation tax liability must be paid 9 months and 1 day after the accounting period end. This deadline is separate from the filing deadline.

Large Company Rules:

Quarterly instalment payments (QIPs) required
Large = tax liability over £1.5m annually
Payments due 6, 9, 12, and 15 months into period
Based on current year estimated liability

Example: Period ending 31 Dec 2024 → Payment due 1 Oct 2025

Other HMRC Filing Deadlines

VAT Returns (MTD)

1 month and 7 days after VAT period end

CbC Reporting

12 months after parent's fiscal year end

FATCA/CRS

31 May following end of reporting year

Pillar Two

15 months after fiscal year end (from 2024)

Companies House Filing Deadlines

Companies House enforces automatic penalties for late filing. From April 2027, all filings must use approved commercial software in iXBRL format.

Statutory Accounts Annual Filing Deadline

9 Months

Private Companies

6 Months

Public Companies

All UK companies must file annual statutory accounts with Companies House. Deadlines vary by company type and are calculated from accounting period end.

Filing Requirements:

iXBRL format mandatory from April 2027
Approved commercial software required
No extensions typically granted
Dormant company accounts still required

Confirmation Statement Annual Company Information

Within 14 Days

Of review date (annual anniversary)

Annual confirmation statement confirming company information is correct, including registered office, directors, secretary, share capital, and shareholders.

Key Information Confirmed:

Registered office address
Directors and company secretary details
Share capital and shareholders
Principal business activities (SIC codes)
People with significant control (PSC)

Late Filing Penalties & Consequences

UK regulators impose automatic penalties for late filing. Understanding penalty structures helps avoid costly compliance failures and potential prosecution.

Companies House Penalties

Statutory Accounts Late Filing

Up to 1 month late £100

Over 1 month, up to 3 months £250

Over 3 months, up to 6 months £500

Over 6 months late £1,500

Public companies pay double these amounts

Other Companies House Penalties

Late confirmation statement £100

Late director appointment filing £150

Late PSC information £150

Persistent late filing (director disqualification) 2-15 years

Company dissolution for persistent non-filing

HMRC Corporation Tax Penalties

Late Filing Penalties

Up to 3 months late £100

3-6 months late £200

6-12 months late £300

Over 12 months late £500

Late Payment Penalties

30 days late 5% of tax due

6 months late +5% of tax due

12 months late +5% of tax due

Daily interest Bank base + 2.5%

Criminal Prosecution Risk

Deliberate evasion or fraudulent returns can result in criminal prosecution with unlimited fines and up to 7 years imprisonment. HMRC actively pursues serious tax crimes.

ISO