First Year Company Accounts: The New Director’s Complete Guide

Setting up a limited company is the easy part. It takes a few minutes and a small fee at Companies House.

What catches most new directors out are the next steps, because your first year of accounts works differently from every year that follows, and two separate bodies want different things from you on different dates.

It’s very much in your favour to get off on a good footing. The admin will become second nature and you’ll stay on the right side of both HMRC and Companies House.

This guide takes you through the whole of your first year. It covers why your first accounting period runs longer than twelve months, the deadlines you have to meet, and everything else you need to know.

Your First Accounting Period Runs Longer Than a Year

Every company has an accounting reference date, or ARD, which marks the end of its financial year. When you incorporate, Companies House sets your first ARD automatically. It falls on the last day of the month in which the first anniversary of incorporation lands.

That single rule is why your first set of accounts covers more than a year. Your first accounting period runs from the day you incorporated to your ARD, which is twelve months plus the extra days to the end of that month.

Imagine you incorporate on 14 June 2025. Your first anniversary is 14 June 2026, so your ARD is set to 30 June 2026. Your first accounting period runs from 14 June 2025 to 30 June 2026, which is twelve months and sixteen days. From then on, your year end stays at 30 June, and each following period is a normal twelve months.

You can change this date if it doesn’t suit you. You’re allowed to shorten your first period, or extend it up to a maximum of eighteen months, by filing a request with Companies House. Shortening it to twelve months or less has one useful effect on your tax return, which the sections below explain.

Two Sets of Accounts for Two Different Bodies

A common source of confusion in the first year is that “doing your accounts” is really two jobs, not one, and each goes to a different place.

1. Companies House needs your statutory accounts for the public record.
2. HMRC needs a Company Tax Return, the CT600, together with your accounts and a tax computation, so it can work out the Corporation Tax you owe.

The two filings draw on the same underlying figures, but they have their own forms, their own rules and, importantly, their own deadlines.

The Deadlines You Have to Meet

First-year deadlines are the ones people most often miss, because they don’t follow the simple nine-month rule that applies later. Three dates matter, and they don’t all fall together.

• Your first accounts are due at Companies House within 21 months of the date you incorporated, or three months from your ARD if that is later. This is far longer than the nine months you’ll get in future years, and it is a deliberate allowance for new companies finding their feet.
• Your Company Tax Return is normally due twelve months after the end of the period it covers, though the split first year is an exception, which the section below explains.
• Your Corporation Tax must be paid within nine months and one day of the end of your accounting period.

So, your tax is due for payment roughly three months before the return that works it out is due for filing. Plenty of new directors assume the two share a deadline, set the money aside for the later date, and end up paying interest. The payment always comes first.

Later years are simpler. Your accounts and your Corporation Tax return settle into deadlines nine and twelve months after your year end, and your tax stays payable nine months and one day after it.

The First-Year Tax Trap: Two Returns and Two Payment Dates

A Corporation Tax accounting period cannot be longer than twelve months, but your first set of accounts covers more than that. HMRC deals with the mismatch by splitting your first period into two, and you have to file a Company Tax Return for each.

Before the dates, one thing to be clear about. Your Corporation Tax clock starts when your company becomes active, meaning when it starts trading or otherwise doing business. For many new companies that is the day they incorporate, but not always. If you don’t start trading until later, your tax periods begin from that later date, and the split below shifts to match.

Take the same company incorporated on 14 June 2025 with a year end of 30 June 2026, and assume it starts trading on the day it is incorporated. Its first period splits into two.

• The first Corporation Tax period runs from 14 June 2025 to 13 June 2026.
• The second runs from 14 June 2026 to 30 June 2026.

Each period has its own CT600 and its own tax computation, both drawn from the same set of statutory accounts. Each also has its own payment date.

There is a special rule for a split first period, though, which gives both returns a single filing date, twelve months after the end of your whole first period of accounts. So the dates stack up as follows:

Two tax payments, roughly three months before the returns are even due, and the Companies House accounts landing on the same day as the first payment. It’s a lot to track in a first year, and it’s a common reason new directors come to us partway through the year.

There is a way to avoid the two-return split. If you shorten your first accounting period to twelve months or less, by moving your ARD back to the month end before, you have a single Corporation Tax period and a single return. It brings your first Companies House deadline forward, so it isn’t right for everyone, but it can make the first year much cleaner. It is worth a conversation before you decide either way.

How You File Your Returns

The way you file changed recently, and it now matters from your very first return. HMRC’s old free service for filing accounts and a Company Tax Return together closed on 31 March 2026. From 1 April 2026, you file your accounts and CT600 with HMRC using commercial software, and a paper return is only accepted if you have a reasonable excuse or you are filing in Welsh.

Your Companies House accounts are a separate filing. For now you can still file those through the Companies House online service, through software, or on paper, so you have more room there than you do with HMRC. That flexibility is changing in 2028, which the filing options section covers.

The practical upshot is that most new directors either buy filing software or, more often, hand the returns to an accountant who already has it. Trying to file your first CT600 the way you might have a few years ago no longer works.

Registering for Corporation Tax

When you incorporate, Companies House tells HMRC, and HMRC sends you a Unique Taxpayer Reference for the company. That is not the same as being registered for Corporation Tax.

You have to register for Corporation Tax within three months of your company becoming active, which means starting to trade or otherwise do business. You do this through your business tax account, and you’ll need details like your company registration number and the date you started trading.

If your company isn’t trading yet, you can tell HMRC it is dormant, and once HMRC accepts that, it won’t normally need a Company Tax Return until it becomes active. You’ll still have to file accounts and a confirmation statement at Companies House, though, so dormant does not mean nothing to do.

Your Filing Options as a New Company

Most companies in their first year are small enough to file simpler accounts, which keeps both the cost and the amount of public information down. Which option you can use depends on your size, measured across three tests.

A company is a micro-entity if it meets at least two of the following for the year.

• Turnover of £1 million or less.
• A balance sheet total of £500,000 or less.
• Ten employees or fewer.

A company is small if it meets at least two of a higher set of limits, being turnover of £15 million or less, a balance sheet total of £7.5 million or less, and fifty employees or fewer. These thresholds rose in April 2025, so older guidance may quote lower figures.

There is a helpful quirk for your first year. In later years you have to meet the size tests for two years running to qualify, but in your first financial year you only need to meet two of the three that year. Since the turnover limit is adjusted for the length of your period, a slightly longer first year gets a slightly higher turnover threshold to match.

A micro-entity can prepare accounts under the simplest standard, FRS 105, doesn’t need a directors’ report, and currently files only a balance sheet at Companies House. A small company uses FRS 102, and can currently file “filleted” accounts, leaving out the profit and loss account and directors’ report. Both are usually exempt from audit, which most new companies are glad to hear.

Take note that, from April 2028, all companies will have to file their accounts with Companies House through commercial software, and the current online and paper routes for accounts will close.

Small companies and micro-entities will have to include a profit and loss account, though they will be able to opt out of having that profit and loss account published on the public register. The option to file abridged accounts will also go.

Don’t Forget the Confirmation Statement

The confirmation statement is not part of your accounts, but it is a first-year obligation that new directors often miss because they lump it in with everything else. It is a yearly check that confirms Companies House holds the right details about your company, such as its directors, shareholders and registered office.

There’s another important change here, too. Identity verification is now mandatory at Companies House. Every director needs their own Companies House personal code, and your confirmation statement will not be accepted until all of your directors have verified their identity, so this is something to sort out when you form the company rather than at the last minute. Persons with significant control have their own verification requirements too.

Your first review period runs for twelve months from incorporation, and you then have fourteen days to file the statement. The fee to file online is £50, and this is not a deadline to treat lightly. You can be fined up to £5,000, Companies House can impose a financial penalty, and your company can be struck off the register if you don’t file. We explain the whole process in our guide to confirmation statements.

What Happens If You Miss a Deadline

Missing your Companies House accounts deadline brings an automatic penalty that increases the longer you leave it.

For a private company, it currently starts at £150 for accounts up to a month late and rises to £1,500 for accounts more than six months late, and the penalty doubles if you file late two years in a row.

HMRC applies its own separate penalties for a late Company Tax Return, and they escalate quickly. For returns due on or after 1 April 2026, you’re charged £200 the day the return is late, another £200 once it is three months late, and then, at six months, HMRC estimates your Corporation Tax bill and adds a penalty of 10% of the unpaid tax, with a further 10% at twelve months. File late three years running and the two £200 penalties become £1,000 each.

On top of all of this, HMRC charges interest on any Corporation Tax paid after its due date, running from the day after payment was due. Because your first year has more moving parts than any that follow, these are easy penalties to trip into and easy ones to avoid with the dates written down.

Getting Your First Year Right

Your first year of company accounts carries more traps than any year after it. The extended accounting period, the split into two tax returns, the payment that falls due before the return, the move to software filing, and the choice of how to file all land at once, on a new director who is usually busy building the business rather than reading Companies House guidance.

At Double Point, we take the whole of it off your desk. We’ll set your accounting reference date sensibly for how you want to trade, register your company for Corporation Tax, prepare and file your statutory accounts and your Company Tax Returns through the right software, and make sure every payment date is diarised well ahead of time.

You keep building the business, and we keep it compliant and on time. You can see how we work on our company accounts page.

If you’ve just started your company, or you’re about to, book a free consultation and we’ll map out your first-year deadlines together.