What Is Form AA01 and Why Does It Matter?
Form AA01 is an official document used by companies registered in the UK to change their Accounting Reference Date (ARD). The ARD determines when your company’s annual financial accounts are due for submission to Companies House.
This form is necessary if a company wants to extend or shorten its financial year for various reasons, such as aligning with tax planning, improving cash flow management, or synchronizing with a parent company’s reporting period.
Where Is Form AA01 Submitted?
The completed Form AA01 must be filed with Companies House—either online (if the digital option is available) or by post. Once processed, Companies House updates the company's records with the new accounting reference date.
Why Would a Business Want to Change Its Accounting Reference Date?
There are several reasons why a company might want to adjust its financial year-end:
Tax Efficiency: Aligning the financial year with other tax deadlines to optimize tax reliefs.
Cash Flow Management: Ensuring financial accounts close during a period of strong liquidity.
Group Reporting: Synchronizing financial statements with a parent company or subsidiaries.
New Business Strategy: Adapting to market changes, investment plans, or operational shifts.
Avoiding Filing Overlaps: Reducing the administrative burden if multiple entities share similar filing deadlines.
Example:
Imagine a UK-based tech startup that incorporated on April 15, 2023. Its default accounting reference date (ARD) would be April 30, 2024. However, the business owner realizes that aligning the company’s ARD with the calendar year (ending December 31) would make financial planning easier. By submitting Form AA01 before the deadline, the company can change its ARD to December 31, 2023.
Rules and Limitations of Changing the Accounting Reference Date
While changing an ARD is relatively straightforward, there are a few important restrictions:
1. How Many Times Can a Company Change Its ARD?
A company can change its ARD at any time before the current filing deadline.
However, a company can only extend its financial year once every five years unless special circumstances apply (e.g., company administration).
2. Maximum Extension and Reduction Period
The financial year can be extended up to 18 months from the last ARD.
The financial year can be shortened by any length (e.g., from 12 months to 6 months).
3. Special Restrictions
The new ARD cannot be set within 7 days of the original date.
Companies cannot extend their ARD if they are already late filing their accounts.
Dormant companies (companies that are not trading) must also file AA01 if they wish to change their ARD.
How to Access Form AA01
You can download Form AA01 from Companies House on their official website. You can also fill it out online. However, as of February 2025, some government links to the form appear to have been moved or updated. The most reliable way to get Form AA01 is to visit the Companies House website directly and search for “AA01 Change of Accounting Reference Date.”
📌 Tip: Always ensure you are using the latest version of the form, as Companies House updates its documentation periodically.
Key Statistics on UK Business Filings (Updated for 2025)
Understanding the importance of compliance and financial filings is easier when looking at real-world data. Here are some relevant UK business statistics as of January 2025:
Statistic | Value |
Number of registered companies in the UK | 5.4 million (Companies House, 2025) |
New companies formed in 2024 | 725,000 |
Companies dissolved in 2024 | 580,000 |
Percentage of companies that change their ARD each year | Approx. 8% |
Most common reason for ARD change | Group reporting alignment |
What Happens If a Company Does Not Change Its ARD in Time?
If a company misses the deadline for filing Form AA01, its original ARD remains in effect. This means:
The company must file accounts based on the existing ARD.
Late filing penalties may apply if accounts are submitted after the due date.
📌 Late Filing Penalty Structure (2025) If a company fails to file accounts on time, the following penalties apply:
Delay Period | Private Company Penalty | Public Company Penalty |
1 day late | £150 | £750 |
Up to 1 month late | £375 | £1,500 |
1-3 months late | £750 | £3,000 |
3-6 months late | £1,500 | £7,500 |
More than 6 months late | £3,000 | £15,000 |
As you can see, failing to manage your accounting reference date properly can lead to significant financial penalties.
Understanding Form AA01 and when to use it is essential for UK business owners. Whether your goal is better tax planning, operational efficiency, or aligning with a parent company, adjusting your accounting reference date can be a strategic financial move.
How to Complete and Submit Form AA01
Now that we’ve covered the basics of Form AA01 and why businesses use it, let’s get into the practical details of how to correctly complete and submit the form to Companies House. This section provides a step-by-step guide, covers the submission process, and highlights the most common mistakes to avoid when changing an Accounting Reference Date (ARD).
Where to Get Form AA01
Before filling out the form, you need to get the latest version. The most reliable way is to visit the official Companies House website and search for Form AA01 (Change of Accounting Reference Date). Since some online links have changed or been removed recently, always make sure you’re using an up-to-date form from gov.uk.
Step-by-Step Guide to Completing Form AA01
Form AA01 is a straightforward, one-page document, but making a mistake can lead to rejection or even penalties if it results in late account filing. Here’s how to complete it correctly:
Step 1: Company Details
At the top of Form AA01, you’ll need to provide your company’s:
Company number (a unique 8-digit number for limited companies or a different format for LLPs)
Company name (must match the name registered with Companies House)
📌 Tip: If you’re unsure about your company number, you can check it on the Companies House website by searching for your company name.
Step 2: New Accounting Reference Date (ARD)
This section requires you to enter the new financial year-end date that you want to set for your company.
You must enter:
The new accounting reference date (day and month format, e.g., 31/12)
Confirmation of whether you’re extending or shortening the financial year
📌 Important Rules to Remember:
You cannot extend the financial year more than once in 5 years, except in certain cases.
The new ARD cannot be within 7 days of the old ARD.
If you’re extending the financial year, the new period must not exceed 18 months unless the company is in administration.
If you’re shortening the financial year, there is no limit to how much you can shorten it.
💡 Example: A company with a current ARD of March 31 wants to align with the calendar year. The business can shorten the period to December 31 of the same year or extend it to a maximum of September 30 the following year.
Step 3: Authorised Signatory
The form must be signed and dated by one of the following:
✔ A company director
✔ A company secretary
✔ A limited liability partnership (LLP) member
📌 Tip: If submitting by post, always check that the signature matches the official record at Companies House to avoid rejection.
How to Submit Form AA01 to Companies House
There are two ways to submit Form AA01:
1. Online Submission (If Available)
While Form AA01 has traditionally been a paper-only submission, some businesses may be eligible for an online submission.
To check if your company can submit online:
Log in to your Companies House account on the Find and Update Company Information page.
Navigate to the file a change section.
Follow the instructions for changing your accounting reference date.
📌 Pros of Online Filing:
Faster processing (usually within 48 hours)
No postal delays
Instant confirmation of receipt
📌 Cons:
Not all companies are eligible for online filing
You must have an authorised Companies House account
2. Postal Submission (Traditional Method)
If online submission isn’t an option, you must send the completed Form AA01 by post to:
📬 Companies House Address (As of 2025): For England and Wales: Companies HouseCrown WayCardiffCF14 3UZ
For Scotland: Companies House4th Floor, Edinburgh Quay 2139 FountainbridgeEdinburghEH3 9FF
For Northern Ireland: Companies HouseSecond Floor, The Linenhall32-38 Linenhall StreetBelfastBT2 8BG
📌 Tip: Always send the form via recorded delivery to track it.
📌 Processing Time:
Standard paper submission: 7-10 working days
Online (if applicable): 24-48 hours
Common Mistakes to Avoid When Filing Form AA01
Making errors when filing Form AA01 can result in delays or rejection. Here are some of the most frequent mistakes:
1. Incorrect Company Information
❌ Error: Providing the wrong company number or misspelling the company name.
✔ Fix: Double-check details on the Companies House search tool.
2. Filing Too Late
❌ Error: Submitting Form AA01 after the current deadline, resulting in penalties.
✔ Fix: File the form at least 14 days before your filing deadline to allow processing time.
3. Extending the Accounting Period Illegally
❌ Error: Trying to extend the financial year more than once in five years without valid grounds.
✔ Fix: Ensure you qualify for an extension before filing.
4. Not Checking If Late Filing Fees Apply
❌ Error: Filing Form AA01 too late and missing the original due date, leading to automatic late filing penalties.
✔ Fix: Know your deadlines! Use the late filing penalty table from Part 1.
What Happens After You Submit Form AA01?
Once Companies House processes Form AA01, they will:
Update the official public record of your company.
Notify you if the form has been accepted or rejected (rejections are typically due to errors in submission).
Send confirmation of the new ARD if approved.
📌 If Your Request Is Rejected:
You must resubmit Form AA01 with corrections before your current deadline.
If rejection leads to late account filing, Companies House will issue penalties.
Key Takeaways:
✅ Form AA01 is a simple but essential document for UK businesses looking to change their Accounting Reference Date.
✅ Correctly completing the form can save time and avoid rejection.
✅ Companies House accepts postal submissions and may allow online filings for some companies.
✅ Errors in submission can result in delays, penalties, or rejected applications.
✅ Always track your filing deadlines to avoid late submission penalties.
How to Fill Form AA01 – A Question by Question Guide
Filling out Form AA01 correctly is essential to ensure that Companies House processes your request without delays or rejections. Below is a step-by-step guide that explains each section of Form AA01, along with sample answers to help you complete the form accurately.
Question 1: What is your company’s full name?
📌 Where to find it on the form: Section 1 – Company details
Sample Answer: XYZ Tech Solutions Ltd
Explanation:
This should be the exact legal name of your company as registered with Companies House.
Any discrepancy in spelling or punctuation could lead to rejection.
You can verify your company’s registered name on the Companies House website.
Question 2: What is your company number?
📌 Where to find it on the form: Section 1 – Company details
Sample Answer:12345678
Explanation:
The company number is a unique 8-digit number issued by Companies House when you register your company.
If you’re an LLP (Limited Liability Partnership), your company number may start with ‘OC’ followed by digits.
Double-check your company number to avoid processing delays.
Question 3: What is your current accounting reference period end date?
📌 Where to find it on the form: Section 2 – Date of accounting reference period
Sample Answer: 31/03/2024
Explanation:
The accounting reference date (ARD) is the financial year-end your company currently has on record.
This should match the date already registered at Companies House.
The format must be DD/MM/YYYY.
Question 4: What date do you want to change your accounting period to?
📌 Where to find it on the form: Section 3 – New accounting reference date
Sample Answer (if shortening the period): 31/12/2023
Sample Answer (if extending the period): 30/09/2025
Explanation:
If you’re shortening the period, you must enter the new, earlier financial year-end.
If you’re extending the period, enter the new, later date (but note you cannot extend beyond 18 months unless your company is in administration).
The date should be in DD/MM/YYYY format.
Question 5: Has the accounting reference period been shortened or extended?
📌 Where to find it on the form: Section 3 – Selection box
Sample Answer:
☑ Shortened (if making the year-end earlier)
☐ Extended (if making the year-end later)
Explanation:
Tick (☑) the appropriate box.
If extending the period, ensure you meet the legal limitations (e.g., cannot extend more than once in 5 years unless special conditions apply).
Question 6: Have you extended the accounting period more than once in the last five years?
📌 Where to find it on the form: Section 4 – Extending more than once in five years
Sample Answer:
☐ Yes (if you’ve extended your ARD before in the past 5 years)
☑ No (if this is your first extension in 5 years)
Explanation:
Companies House has strict rules on how often you can extend your financial year.
If you tick Yes, you must provide a valid reason (e.g., aligning with a parent company’s ARD).
Question 7: If extending again within five years, which exemption applies?
📌 Where to find it on the form: Section 4 – Check the applicable exemption
Sample Answer:
☑ The company is in administration
☐ You have specific approval from the Secretary of State (attach proof)
☐ The company is aligning with a UK-based parent or subsidiary
☐ The company is an overseas entity filing in the UK
Explanation:
If extending more than once in five years, you must qualify under one of the four exemptions.
Select the correct option and provide supporting documents if required.
Question 8: Who is signing the form on behalf of the company?
📌 Where to find it on the form: Section 5 – Signature
Sample Answer: Name: John SmithRole: Director
Explanation:
This form can be signed by:
A Director
A Company Secretary
An LLP Member
An Administrator (if applicable)
If you are an overseas company, a Permanent Representative can sign.
Question 9: Where are you sending the form?
📌 Where to find it on the form: Address section
Sample Answer (for England & Wales companies):
📬 Companies HouseCrown Way, Cardiff, CF14 3UZ
Explanation:
Different Companies House offices process forms based on your company’s registration location.
Always send to the correct regional Companies House office (England/Wales, Scotland, or Northern Ireland).
If you submit online via WebFiling, postal submission is not necessary.
Question 10: Have you checked all required details before submission?
📌 Where to find it on the form: Final checklist
✔ Confirm the company name and number are correct
✔ Ensure you’ve entered a valid new ARD
✔ Check whether the ARD change follows legal restrictions
✔ Ensure the form is signed by an authorized person✔ Verify the filing deadline to avoid penalties
📌 Important Reminder:
Incorrect or incomplete forms will be rejected.
Once Companies House accepts the change, it is legally binding.
Filing a late ARD change can result in automatic late-filing penalties for missing the original deadline.
Final Thoughts on Filling Form AA01
Form AA01 is straightforward, but accuracy is crucial. Here are the key takeaways:
✅ Ensure you meet the legal conditions for extending or shortening your ARD.
✅ Double-check your company details before submitting the form.
✅ Only extend your ARD once every five years unless exemptions apply.
✅ Use WebFiling for faster processing if available.
✅ Send the completed form to the correct Companies House office.
Filing this form correctly ensures that your company maintains compliance and avoids unnecessary fines. If in doubt, consult a professional accountant or corporate services provider. 🚀
Strategic Use of Form AA01 for UK Businesses
Now that we’ve covered what Form AA01 is, how to complete and submit it, and common mistakes to avoid, let’s dive into real-world applications and strategic reasons for changing the accounting reference date (ARD). This section will cover how an ARD change affects tax planning, cash flow management, and compliance. We’ll also discuss practical scenarios where businesses can benefit from adjusting their financial year-end.
How Changing the Accounting Reference Date Affects Tax Planning
One of the primary reasons UK businesses change their accounting reference date (ARD) is to optimize tax planning. Adjusting your financial year-end can help minimize tax liability, delay payments, or align with other business cycles.
1. Deferring or Accelerating Corporation Tax Liabilities
A company’s corporation tax bill is based on its accounting period profits. By shifting the ARD, a company can:
Defer profits into the next tax year to delay tax payments.
Shorten the accounting period to reduce taxable profits for a specific year.
💡 Example: A business with a 31 March ARD made high profits in 2024 and expects lower profits in 2025. By shortening the accounting period to 31 December 2024, it shifts part of its profits into a new tax year, reducing immediate tax liability.
📌 Important Consideration:
HMRC may scrutinize ARD changes that appear to be purely for tax avoidance.
The company must still comply with quarterly tax payment rules.
2. Aligning with Group Companies for Consolidated Accounts
If a company is part of a larger corporate group, aligning the ARD can simplify financial reporting and reduce administrative burdens.
💡 Example: A UK subsidiary has an ARD of 30 June, but its parent company’s financial year ends on 31 December. By changing its ARD to 31 December, the UK subsidiary can align its accounts, making group consolidations easier.
📌 Impact on Audits:
If a company requires an audit, an ARD change might affect audit timelines.
Many companies prefer to align ARD with the tax year (5 April) or calendar year (31 December).
How ARD Changes Impact Cash Flow Management
An accounting period adjustment can affect cash flow planning, especially for companies with seasonal revenue fluctuations.
3. Avoiding Financial Year-End Cash Crunches
For businesses with high seasonal sales, an ARD change can help prevent financial pressure when tax and VAT payments are due.
💡 Example: A retail business with a 31 January ARD earns most of its revenue in November-December due to Christmas sales. By shifting the ARD to 30 April, it can delay corporation tax payments, keeping more cash available for Q1 operational costs.
📌 Key Benefit:
Helps businesses smooth cash flow by ensuring tax liabilities fall in a stronger revenue period.
Regulatory and Compliance Considerations When Changing ARD
While adjusting the financial year-end can have financial benefits, companies must stay compliant with UK company law.
4. Avoiding Overlapping Filing Deadlines
Some companies change their ARD to prevent filing multiple reports at the same time (e.g., VAT returns, company accounts, tax filings).
💡 Example: A company with a 31 March ARD finds that its VAT return and annual accounts are due in the same month, creating an administrative burden. By shifting the ARD to 30 June, it can space out deadlines for easier compliance.
📌 Check Before You File:
Ensure that the ARD change does not create unexpected filing overlaps.
Review your tax deadlines with your accountant.
How Changing ARD Affects Loan Applications and Investor Reports
Lenders, investors, and financial institutions rely on annual financial statements to assess a company’s financial health.
5. Ensuring Better Financial Presentation for Investors
If a company is seeking investment or applying for a loan, it may want to adjust its ARD to showcase a stronger financial position.
💡 Example: A startup is preparing for a fundraising round in early 2026. By adjusting its ARD to 31 December 2025, it can ensure that its financial statements show a full profitable year, improving investor confidence.
📌 Considerations for Investors:
Some investors may not favor frequent ARD changes, as it affects financial consistency.
Companies applying for loans should check with banks before changing ARD.
Real-World Case Studies of ARD Changes in the UK
Case Study 1: Tech Startup Aligning with Parent Company
📌 Company: UK-based SaaS company
📌 Old ARD: 30 September
📌 New ARD: 31 December
Reason for Change: The company was acquired by a US-based parent company with a 31 December financial year-end. To streamline financial reporting and ease tax compliance, it shifted its ARD.
Outcome:
Consolidation with the parent company became easier.
The company avoided duplicate audit requirements.
Accounting costs were reduced.
Case Study 2: Retail Chain Optimizing Seasonal Revenue Cycles
📌 Company: UK fashion retailer
📌 Old ARD: 31 March
📌 New ARD: 30 June
Reason for Change: The business makes most of its profits in Q4 (October-December) but faces high stock purchasing costs in Q1. By shifting the ARD, it aligned its financial reporting with its busiest season.
Outcome:
The company had more liquidity during tax payment periods.
Investors saw higher profit margins in annual reports.
Should Your Company Change Its ARD? Key Questions to Ask
Before filing Form AA01, ask yourself these key questions:
✔ Does changing the ARD help with tax planning?
✔ Will it improve cash flow management?
✔ Does it align with a parent company’s financial year?
✔ Are there any compliance risks?
✔ Will the change affect investor or lender confidence?
If the answer to any of these questions is yes, an ARD change may be beneficial.
📌 Final Tip: Always consult an accountant or financial advisor before making changes.
Final Thoughts on Form AA01
Changing your company’s Accounting Reference Date (ARD) using Form AA01 can be a strategic financial decision if done correctly. From tax optimization to cash flow management, businesses can use ARD adjustments to their advantage—but they must remain compliant with UK company law.
To summarize:
✅ Form AA01 is essential for adjusting your company’s financial year-end.
✅ Changing the ARD can help with tax deferrals, investor confidence, and cash flow management.
✅ There are strict rules on how often a company can extend its financial year.
✅ Always consider compliance, regulatory deadlines, and business strategy before filing.
If you’re considering filing Form AA01, now is the time to review your company’s financial calendar and determine whether an ARD change is the right move for your business! 🚀
FAQs
Q1: Can you file Form AA01 online, or is it only available as a paper submission?
A: As of February 2025, Form AA01 is primarily a paper submission, but some companies may have an option to file online via the Companies House WebFiling service. You should check the Companies House website for the latest online filing availability.
Q2: How long does Companies House take to process Form AA01?
A: The processing time for Form AA01 depends on the submission method. Online filings (if available) are processed within 48 hours, while postal submissions take approximately 7–10 working days. Delays may occur during peak filing seasons.
Q3: Can you use Form AA01 to change the accounting reference date for a dormant company?
A: Yes, a dormant company can use Form AA01 to change its accounting reference date, as long as it complies with Companies House regulations and files the form before any filing deadlines.
Q4: Will changing your accounting reference date using Form AA01 affect your tax deadlines with HMRC?
A: Changing the ARD may impact corporation tax deadlines, especially if it results in a longer or shorter accounting period. You should notify HMRC of any changes to ensure compliance with tax obligations.
Q5: Is there a fee for filing Form AA01 with Companies House?
A: No, as of February 2025, Companies House does not charge a fee for submitting Form AA01, whether filed by post or online (if applicable).
Q6: Can you change your accounting reference date multiple times within five years if your company is newly incorporated?
A: No, the five-year restriction applies to all companies, including newly incorporated ones. However, exceptions exist for companies in administration, those aligning with a parent company, or those granted approval by the Secretary of State.
Q7: What happens if you make a mistake on Form AA01 after submitting it?
A: If Companies House rejects your Form AA01 due to errors, you will need to correct the mistakes and resubmit it before your deadline to avoid penalties.
Q8: Can Form AA01 be used to change an accounting reference date for an LLP (Limited Liability Partnership)?
A: Yes, LLPs can use Form AA01 to change their accounting reference date, following the same process as limited companies. The LLP’s designated members must sign and submit the form.
Q9: Will changing your accounting reference date affect VAT reporting periods?
A: No, changing the ARD does not automatically change VAT reporting periods. You must contact HMRC separately if you wish to align VAT periods with your new financial year-end.
Q10: Can you submit Form AA01 after your accounts are already overdue?
A: No, you cannot use Form AA01 to change an accounting reference period for which accounts are already overdue. You must file overdue accounts first before applying for a date change.
Q11: Can sole traders or partnerships (non-LLPs) use Form AA01?
A: No, Form AA01 is only for limited companies and LLPs registered with Companies House. Sole traders and standard partnerships manage their accounting periods through HMRC, not Companies House.
Q12: If you extend your financial year, when is your next set of accounts due?
A: If you extend your financial year using Form AA01, your next set of accounts will be due within 21 months of your company’s incorporation date or within 3 months of the new accounting reference date, whichever is later.
Q13: Can a company change its accounting reference date to any day of the year?A: Yes, a company can change its ARD to any date, but it must comply with legal restrictions, such as the 18-month maximum extension rule and the five-year extension limitation.
Q14: Do you need shareholder approval to file Form AA01?
A: No, Form AA01 does not require shareholder approval. It only requires a signature from a company director, secretary, or other authorized personnel.
Q15: If you extend your financial year beyond 12 months, do you need to file two tax returns with HMRC?
A: Yes, if your new accounting period exceeds 12 months, HMRC requires you to submit two separate corporation tax returns—one covering the first 12 months and another covering the remaining period.
Q16: Can you change your accounting reference date if your company is in liquidation?
A: No, a company in liquidation cannot change its ARD. Form AA01 is only applicable to active or dormant companies that are not undergoing liquidation or dissolution.
Q17: What supporting documents do you need when filing Form AA01 for an extension beyond five years?
A: If extending beyond five years, you must provide supporting documents such as proof of administration, a letter from the Secretary of State, or documentation showing alignment with a parent or subsidiary undertaking.
Q18: Will changing the accounting reference date affect your Companies House filing deadlines for confirmation statements?
A: No, changing your ARD does not affect the deadline for filing confirmation statements (previously known as annual returns), which must still be filed annually based on your company’s incorporation date.
Q19: How does Companies House notify you once Form AA01 has been processed?
A: Companies House will update your public record and typically send an email or letter confirming the acceptance of your ARD change. You can also check the status online.
Q20: Can you reverse an accounting reference date change after filing Form AA01?A: No, once Companies House accepts Form AA01, the change is final and cannot be reversed. You would need to file another Form AA01 to change it again, but only if you meet eligibility criteria.
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