When Are My First UK Company Accounts Due?

If you have recently incorporated a UK limited company, one of the first deadlines you need to understand is the date your first company accounts are due at Companies House. For most private limited companies, the first accounts are due within 21 months of incorporation when the first accounts cover more than 12 months. This is different from the deadline for subsequent annual accounts, which is normally 9 months after the company’s accounting reference date.

The important point is that your Companies House accounts deadline and Corporation Tax deadline are not necessarily the same. New company owners often confuse the two, which can lead to missed filings or unnecessary penalties. This guide explains how to calculate your first accounts deadline, what the accounting reference date means, how the first accounts differ from later accounts, and what new founders should do to stay compliant.

The Short Answer: When Are First Company Accounts Due?

For a typical UK private limited company, your first accounts are generally due 21 months after the date your company was incorporated, provided the first accounts cover more than 12 months. There is also a specific rule involving three months from the accounting reference date, with the longer period applying. For example:

• Company incorporated: 1 January 2025
• First accounting reference date: 31 January 2026
• First accounts cover: 1 January 2025 to 31 January 2026
• Companies House filing deadline: 1 October 2026

That first accounting period is longer than 12 months, which is why the company gets the special first-accounts filing period. For subsequent years, a private company normally has 9 months after the end of its accounting reference period to file its accounts with Companies House.

Why Are First Company Accounts Usually Due After 21 Months?

The reason the first deadline can appear surprisingly long is that your company's first financial year normally starts on its incorporation date, rather than simply running for 12 months. Companies House automatically determines the company's first accounting reference date (ARD). For a new company, the first ARD is normally the last day of the month in which the anniversary of incorporation falls.

Example: Company Incorporated in May

Suppose you incorporate your company on 11 May 2026. Your first accounting reference date will normally be 31 May 2027. Your first accounts therefore cover approximately: 11 May 2026 → 31 May 2027, That is around 12 months and three weeks.

Companies House confirms that first accounts commonly cover more than 12 months for this reason. The filing deadline for those first accounts will normally fall within the special first-accounts period rather than simply being calculated as nine months after the ARD.

What Is an Accounting Reference Date?

Your accounting reference date is the date your company's financial year normally ends for Companies House purposes. Think of it as your company's annual accounting cut-off date. For a newly incorporated company, Companies House normally sets the first ARD as the last day of the month in which the incorporation anniversary occurs. For example:

After the first year, the accounting reference date normally remains the same each year unless you formally change it. This is important because your ARD is not necessarily 12 months after incorporation.

First Accounts vs Subsequent Accounts

One of the easiest ways to understand the system is to separate your first accounts from everything that follows.

First company accounts

For a private company whose first accounts cover more than 12 months, the filing period is generally: 21 months from incorporation, or three months from the accounting reference date whichever is longer.

Subsequent annual accounts

After the first accounts have been filed, a private company normally has: 9 months from the accounting reference date to deliver its next accounts to Companies House. This creates an important distinction: Your first accounts are not normally due nine months after your first year ends. That nine-month rule generally applies to subsequent accounts.

A Worked Example of First Accounts

Imagine that ABC Global Ltd is incorporated on 15 February 2026. Its first accounting reference date will normally be 28 February 2027. Its first accounts therefore cover: 15 February 2026 to 28 February 2027, Because the first accounts cover more than 12 months, the company benefits from the special first-accounts filing period. The 21-month point from incorporation is: 15 November 2027

So, subject to the specific calculation rules, this is the date to work around when planning the Companies House filing. The safest approach is not to rely on mental calculations. Companies House allows you to check the company's actual filing deadline using its company information service.

Your Companies House Deadline Is Not Your Corporation Tax Deadline

This is one of the most important distinctions for new directors. Your company has separate obligations to Companies House and HM Revenue & Customs (HMRC). For a typical private limited company:

These dates can be different because Companies House accounts and Corporation Tax accounting periods operate under different rules.

Why this matters for a new company

Your first Companies House accounts can cover more than 12 months, while a Corporation Tax accounting period cannot exceed 12 months.As a result, a company may sometimes need to submit two Corporation Tax returns covering the period represented by its first accounts. That is why a founder should never assume: “My first Companies House accounts aren't due yet, so I don't have any tax filing obligations.” The two systems need to be managed separately.

What Do Your First Company Accounts Include?

The exact contents depend on the company's size, circumstances and applicable filing requirements. In general, statutory accounts are prepared to report the company's financial performance and financial position. They can include items such as:

• balance sheet
• profit and loss account
• notes to the accounts
• directors' report, where applicable
• accounting policies and other required disclosures

Small and micro-entity companies may qualify for simpler accounts and filing requirements. However, small does not mean exempt from filing. Companies House states that all companies must file annual accounts, including dormant and non-trading companies, subject to specific exemptions that may apply to particular entities or circumstances.

What If My Company Has Never Traded?

A company that has not traded may still have to file accounts. Being dormant does not automatically remove the company's Companies House filing obligations. If your company is dormant, you may be able to file dormant company accounts rather than trading accounts, depending on the circumstances. This is particularly relevant to founders who incorporate a company months before launching the business.

For example, if you form a company in January but do not start trading until October, the company may still have Companies House reporting obligations during the period before trading begins. Do not simply ignore the company because it has generated no revenue.

What Happens If You File Your First Accounts Late?

Late filing can result in an automatic penalty. Companies House states that the director is responsible for ensuring accounts are delivered within the permitted period, and the penalty applies when accounts are delivered late. For a private company, late filing penalties increase according to how late the accounts are. The practical lesson is simple: do not treat the filing deadline as the date you should start preparing your accounts.

Your accountant may need time to reconcile bank transactions, identify expenses, prepare adjustments and finalise the accounts before they can be filed. There is also a technical risk in leaving filing until the final day. Companies House explains that accounts must actually be received and accepted, not merely sent, and rejected accounts can still become overdue if the deadline has passed.

Can You Change Your Company's Accounting Reference Date?

Yes. A company can generally change its accounting reference date by filing the appropriate notification with Companies House. This can be useful where a business wants its financial year to align with:

• a parent company's year end
• a group's reporting cycle
• a particular commercial period
• its preferred accounting timetable

However, changing the ARD can affect the length of the accounting period and the resulting filing deadline. Companies House also imposes restrictions on extending accounting periods. An accounting period generally cannot be extended beyond 18 months from its start date, except in specific circumstances.

Most importantly, an ARD change must be made before the relevant accounts become overdue. Once the accounts are overdue, changing the accounting reference date is too late to avoid that filing problem.

What New Company Directors Should Do

The first year of a company can involve incorporation, opening a bank account, registering for taxes, hiring staff, issuing invoices and building the business. Accounts deadlines can easily get lost in the background. A better approach is to create a compliance calendar immediately after incorporation.

1. Record your incorporation date

Keep the exact date your company was incorporated.

2. Check your accounting reference date

Companies House will establish the company's first ARD based on its incorporation date.

3. Check your actual filing deadline

Do not rely solely on a generic “21 months” rule. Confirm the company's filing deadline through Companies House.

4. Separate Companies House and HMRC deadlines

Create separate reminders for:

• Companies House accounts
• Corporation Tax payment
• Company Tax Return
• VAT returns, if VAT registered
• PAYE filings, if you employ staff
• confirmation statements

5. Start preparing accounts early

Waiting until the final few weeks creates unnecessary pressure and increases the risk of errors. For international founders, this is particularly important. A UK company can have directors or shareholders living overseas, but the company's UK filing obligations still need to be managed properly.

Can You Get More Time to File?

In limited circumstances, a company can apply for an extension to its accounts filing deadline where an event outside its control prevents filing. Examples can include an unexpected illness or destruction of company records.

The application must be made before the existing filing deadline. Waiting until after the deadline has passed will not normally solve the problem. An extension should therefore be treated as a contingency measure, not as part of your normal filing strategy.

First Accounts Checklist for New UK Companies

Before your first accounts deadline arrives, make sure you have:

• confirmed your company's incorporation date
• checked your accounting reference date
• confirmed the Companies House filing deadline
• maintained complete accounting records
• reconciled company bank accounts
• recorded income and business expenses
• identified company assets and liabilities
• checked whether the company is trading or dormant
• considered Corporation Tax obligations separately
• prepared the appropriate statutory accounts
• obtained director approval before filing
• allowed enough time for filing and possible corrections

Companies House requires directors to approve accounts before they are filed. For founders using IncorpUK, a UK company formation and management platform for global founders, understanding these dates early can help prevent the common mistake of treating incorporation as the end of the compliance process. In reality, incorporation is the beginning of an ongoing set of filing responsibilities.

Frequently Asked Questions

When are first accounts due for a UK limited company?

For most private limited companies whose first accounts cover more than 12 months, the deadline is generally 21 months after incorporation, subject to the rule comparing this with three months from the accounting reference date.

Are first company accounts due 12 months after incorporation?

Not usually. A new company's first accounting period normally runs from incorporation to its first accounting reference date, which is usually the last day of the month in which the incorporation anniversary falls. The first period therefore commonly exceeds 12 months.

When are second-year company accounts due?

For a private company, subsequent annual accounts are normally due 9 months after the end of the accounting reference period.

Are Companies House accounts and Corporation Tax returns due on the same date?

No. They have different filing rules. Corporation Tax is normally payable 9 months and 1 day after the end of the Corporation Tax accounting period, while the Company Tax Return is normally due 12 months after that accounting period ends.

Does a dormant company need to file its first accounts?

Yes. Dormant companies generally still have Companies House filing obligations. Companies House confirms that companies must file annual accounts even where they are dormant or not trading, subject to applicable exemptions.

What happens if my first accounts are late?

Companies House can impose an automatic late filing penalty. The penalty increases depending on how late the accounts are filed.

Can I change my company's accounting reference date?

Yes, subject to Companies House rules. A company can change its accounting reference date, but the timing and length of the resulting accounting period matter.

Can I get an extension for my first accounts?

An extension may be available where an event outside the company's control prevents timely filing. The application must be made before the existing deadline.

Conclusion

For most new UK private limited companies, the first Companies House accounts deadline is 21 months from incorporation when the first accounts cover more than 12 months, subject to the specific first-accounts calculation. But the headline number is only part of the picture.

Your company's accounting reference date, Companies House filing deadline, Corporation Tax payment date and Company Tax Return deadline are separate compliance dates. Understanding the distinction from the beginning makes it much easier to avoid missed filings and unnecessary penalties.

The best approach is to check your company's exact deadlines immediately after incorporation, keep accounting records from day one and prepare your first accounts well before the filing date. For a new founder, good compliance is not something to deal with once a year. It is part of building a company that can operate, grow and remain in good standing with the UK authorities.