Choosing your company’s year-end date

When you set up a limited company, its first year-end is set for you. Many directors never think about it again. But the date your company’s financial year ends affects when your accounts are prepared, when your tax is due and how busy you are at certain times of year.

Here is what to think about when choosing a year-end, and how to change it if the current one doesn’t suit you.

How the year-end is set

When a company is incorporated, Companies House sets its accounting reference date automatically. It is the last day of the month in which the anniversary of incorporation falls. So a company formed on 10 May would have a year-end of 31 May.

That date then drives the company’s deadlines. Private companies file their annual accounts with Companies House, and pay their Corporation Tax and file a Company Tax Return with HMRC, by deadlines worked out from the end of each accounting period. GOV.UK’s guidance on annual accounts and paying Corporation Tax sets out each one.

What to think about when choosing a date

• Your busy season. If your business is seasonal, a year-end just after your quietest period can make stocktaking and year-end work easier, and means the accounts show a full cycle of trading.
• Your workload. Year-end work takes time. Choosing a date that doesn’t clash with your peak trading months, or with other commitments, makes it easier to give the accounts the attention they need.
• Cashflow. Your Corporation Tax payment date follows from the year-end. Think about when cash is usually strongest in your business.
• Matching the tax year. Some directors prefer a year-end of 31 March or 5 April, close to the tax year, because it makes it simpler to compare company profits with their personal tax position.
• Group companies. If you have more than one company, aligning their year-ends usually makes life simpler.

How to change your year-end

You can change your company’s year-end for the current financial year or the one immediately before it. You do this with Companies House, online or by post.

There are limits. You can shorten a financial year as many times as you like. You can usually only lengthen it once every five years, and then to no more than 18 months, unless an exception applies, for example aligning with a parent or subsidiary company. You can’t change your year-end once the accounts for that period are overdue. The rules are on GOV.UK’s page on changing your company’s year end.

Changing the year-end normally changes your filing deadline too. If your new deadline has already passed when you make the change, a late filing penalty will apply, so check the dates first.

What it means for Corporation Tax

A company’s accounting period for Corporation Tax can’t be longer than 12 months. If you lengthen your financial year beyond 12 months, the company will have two Corporation Tax accounting periods for that set of accounts, each with its own return and payment date. You must also tell HMRC if you’ve shortened or lengthened your financial year. GOV.UK explains Corporation Tax accounting periods.

Because of this, a change of year-end can bring a tax payment forward or move it back. It’s worth working through the timing before you file the change.

Sources

Our main sources are HMRC and GOV.UK:

• Change your company’s year end
• Prepare annual accounts for a private limited company
• Corporation Tax: accounting periods and deadlines
• Pay your Corporation Tax bill

Talk to us before you change your year-end

If your year-end doesn’t suit your business, we can look at the options with you, including the effect on your deadlines and your Corporation Tax. Call us on 020 7164 0225, send us a WhatsApp message or email your tax question to hello@ibandco.co.uk.

You can also read about our end of year accounts and Corporation Tax planning services.

First published 14 May 2024. Tax content checked on 9 October 2026. This article reflects the rules at the date it was first published. Where something has changed since, we’ve added an update note. Rules and rates change, so please check with us before acting.

Please note: this article is general information based on our understanding of UK tax rules at the date shown above. It is not advice for your circumstances, and tax rules and rates can change. Please speak to us before acting on it.