You have incorporated your limited company, started trading, kept your records organised, and prepared for your first set of accounts. Then your accountant tells you something unexpected: your First Company Accounts may require two Corporation Tax returns.

For many new directors, this sounds like a mistake. After all, there is only one company, one set of accounts, and one year of business activity. However, Companies House and HMRC follow different rules when deciding how reporting periods work.

In this guide, we explain why two Corporation Tax returns may be required, how the rules work, and what steps you should take before filing your first company accounts.

Key Takeaways

  • Your first statutory accounts can cover a period longer than 12 months.
  • HMRC Corporation Tax accounting periods cannot exceed 12 months.
  • A company may need two CT600 returns covering its first accounting period.
  • Each Corporation Tax period has separate payment and filing deadlines.

Why Two Corporation Tax Returns Can Be Required

The reason comes down to the difference between a company’s accounting period for Companies House and its accounting period for Corporation Tax.

When a limited company is incorporated, Companies House creates an accounting reference date. This determines when the company’s annual accounts are prepared. A company’s first accounts usually begin on the incorporation date and continue until the end of the month in which its first anniversary falls.

(Source: Your limited company’s first accounts and Company Tax Return – GOV.UK)

Companies House allows this longer first accounting period, but Corporation Tax works differently. HMRC limits Corporation Tax accounting periods to a maximum of 12 months. If the accounts cover a longer period, the company must file two Corporation Tax returns to cover the full period. 

The company does not prepare two separate sets of accounts. Instead, the accountant prepares one set of statutory accounts and then creates separate Corporation Tax calculations for each HMRC accounting period.

(Source: Accounting periods for Corporation Tax – GOV.UK)

First Company Accounts Explained

Your first company accounts are the first statutory financial statements submitted to Companies House. They show how the company has performed since incorporation and provide details of its financial position.

They normally include:

• Balance sheet.
• Profit and loss account.
• Notes to the accounts.
• Accounting policies.
• Information about directors.

Many new companies assume their first accounts and first Corporation Tax return cover the same dates. This is often not the case. Your statutory accounts may cover 15 months, while HMRC may split that same period into two Corporation Tax accounting periods.

This distinction is one of the most important compliance points for newly incorporated companies.

Example of Two Corporation Tax Returns

Consider the following example:

• A company is incorporated on 1 February 2026
• The company prepares its first accounts to 30 April 2027
• The statutory accounts period is 1 February 2026 to 30 April 2027

However, HMRC splits the period as follows:

Corporation Tax period

Filing requirement

1 February 2026 to 31 January 2027

First Corporation Tax return

1 February 2027 to 30 April 2027

Second Corporation Tax return

The company prepares one set of annual accounts covering the entire 15-month period. However, HMRC receives two CT600 returns because each Corporation Tax accounting period must not exceed 12 months. 

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How Corporation Tax Accounting Periods Work

A Corporation Tax accounting period cannot exceed 12 months.

Where your company’s accounts cover more than 12 months, the period is divided into separate Corporation Tax accounting periods. The company’s taxable profits must then be allocated between those periods.

This makes accurate bookkeeping particularly important. Sales, expenses, payroll, assets and other transactions need to be recorded correctly so the Corporation Tax calculations can be prepared accurately.

Deadlines for First Corporation Tax Returns

When two Corporation Tax returns are required, each return has its own deadlines.

Requirement

Deadline

Corporation Tax payment

9 months and 1 day after the end of the accounting period

Corporation Tax return filing

12 months after the end of the accounting period

First company accounts filing

21 months after incorporation

Using the previous example, the company may have:

• One Corporation Tax payment deadline for the period ending 31 January 2027.
• Another Corporation Tax payment deadline for the shorter period ending 30 April 2027.

Many directors are aware of their Companies House accounts deadline but overlook that HMRC deadlines operate separately.

(Source: Accounts and tax returns for private limited companies)

Corporation Tax Rates and Tax Planning

For accounting periods beginning on or after 1 April 2023:

• Companies with taxable profits of £50,000 or less may qualify for the 19% small profits rate.
• Companies with taxable profits above £250,000 generally pay the 25% main rate.
• Companies between these thresholds may qualify for marginal relief.

The thresholds can be reduced where a company has associated companies.

Common Mistakes New Companies Make

New company directors often assume that their first statutory accounts and Corporation Tax return will cover the same dates. They may also overlook:

• Whether their first accounting period exceeds 12 months.
• The separate Corporation Tax deadlines.
• Keeping complete bookkeeping records.
• VAT registration requirements.
• Payroll obligations.
• Confirmation Statement deadlines.

Understanding these requirements early can help prevent late filings and unnecessary penalties.

Records You Should Keep

HMRC expects companies to maintain sufficient records to support their Corporation Tax returns. Your records should normally include:

• Sales invoices.
• Purchase invoices.
• Bank statements.
• Expense receipts.
• Payroll records.
• VAT records.
• Loan agreements.
• Director transactions.

Good record keeping makes it easier to prepare statutory accounts and reduces the risk of errors during Corporation Tax calculations.

First Company Accounts Checklist

Before filing your first accounts, directors should:

• Confirm the accounting reference date.
• Check whether the first accounting period exceeds 12 months.
• Confirm whether two Corporation Tax returns are required.
• Ensure bookkeeping records are complete.
• Review expenses and director transactions.
• Confirm HMRC filing deadlines.
• Keep supporting documentation.

Taking these steps early prevents many common compliance problems.

Conclusion

Your First Company Accounts can create unexpected compliance requirements if the accounting period is longer than 12 months. While Companies House may accept one longer set of accounts, HMRC may require two separate Corporation Tax returns.

Understanding this difference helps directors avoid missed deadlines, incorrect tax calculations, and unnecessary complications. Keeping accurate records and seeking advice before deadlines approach can make the process much easier.

If you are preparing your first company accounts and are unsure whether you need one or two Corporation Tax returns, we can help you understand your filing requirements and prepare your accounts and Corporation Tax returns.

Frequently Asked Question

Can I change my company year end to avoid two Corporation Tax returns?
Changing your accounting reference date may affect the length of your first accounting period, but it is not always the best solution. Directors should consider the wider accounting and tax implications before making changes. Professional advice can help determine the most suitable approach.
Do two Corporation Tax returns mean I will pay more tax?
No. The number of Corporation Tax returns does not determine how much tax your company pays. The tax liability depends on your taxable profits. However, profits and expenses must be allocated correctly between the two accounting periods to ensure the calculation is accurate.
Will needing two Corporation Tax returns increase my accounting fees?
It may increase the amount of work required because your accountant needs to prepare an additional Corporation Tax calculation and return. The cost depends on the complexity of your records and transactions. Good bookkeeping can help reduce unnecessary preparation time.
What happens if I submit my company accounts but forget the second Corporation Tax return?
Companies House accounts and HMRC Corporation Tax returns are separate requirements. Filing your accounts does not complete your Corporation Tax obligations. If a required return is missed, HMRC may charge late filing penalties and interest on unpaid tax.
Do dormant companies need two Corporation Tax returns for their first accounts?
A dormant company may still have reporting obligations depending on its circumstances. If it has no Corporation Tax liability, the requirements may differ. Directors should confirm their position with HMRC, especially if the company had any transactions before becoming dormant.