What is an accounting year end date?

An accounting year end date is the last day of your company's financial year, also known as the accounting reference date. This determines when your annual accounts and corporation tax return are due to be filed with Companies House and HMRC.

How long is the first accounting period for a new company?

The first accounting period can be anywhere from 6 to 18 months long. Companies House automatically sets your first accounting reference date to the last day of the month, 12 months after your incorporation date, but you can change this if needed.

Can I change my company's year end date?

Yes, you can change your accounting reference date by filing form AA01 with Companies House. You can shorten the current accounting period to any length, or extend it by up to 18 months (but only once every 5 years for extensions).

What happens if I miss my accounting year end deadline?

Missing your accounts filing deadline results in automatic penalties from Companies House: £150 for up to 1 month late, £375 for up to 3 months late, £750 for up to 6 months late, and £1,500 for over 6 months late. Repeated failures can lead to company dissolution.

Should I choose 31st March as my year end date?

31st March aligns with the UK tax year and can simplify dividend planning, but accountants are extremely busy during this period which may cause delays. Consider your business needs, cash flow patterns, and accountant availability when choosing your date.

When are my accounts due after the year end?

Annual accounts must be filed with Companies House within 9 months of your accounting year end date. Corporation tax returns are due to HMRC 12 months after the year end, with any tax owed due 9 months and 1 day after the year end.

Can GoForma help me choose the right year end date?

Yes, our experienced accountants can advise on the optimal year end date for your business during a free consultation. We consider your industry, cash flow patterns, tax planning needs, and business objectives to recommend the best date for your circumstances.

What's included in GoForma's year end accounts service?

Our year end service includes preparation and filing of annual accounts, corporation tax returns, confirmation statements, and dedicated support from your personal accountant. Packages start from £79/month and include all statutory filings and deadlines management.

What is your First Accounting Year End Date?

Your accounting year end is the date when your business financial year concludes and you must prepare annual accounts, with limited companies required to file these with Companies House within nine months and sole traders needing to include the information in their Self Assessment tax return to HMRC.

Last updated Feb 2, 2026

1 min read

Written by Jordan MaceyAAT

What is your First Accounting Year End Date?

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<p>The first accounting year end date for a new company is the last day of the month in which the first anniversary falls on. For example, if your company was incorporated on 15 January 2021, the first accounting year end date will be 31 January 2022.</p>

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What is your First Accounting Year End Date?

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