Limited Company Filing Obligations: The Complete Guide for Directors

Every UK limited company must file annual accounts with Companies House, a Company Tax Return (the CT600) with HMRC, and an annual confirmation statement, each by a separate statutory deadline. Company accounts filing with HMRC and Companies House is a legal duty that falls on the directors personally, not on the accountant, and missing a deadline triggers automatic penalties that escalate the longer the delay continues. The two filings are separate: Companies House receives the statutory accounts, while HMRC receives the CT600 and the tax computation. Blue Tick Accountants, a Guildford-based UK tax advisory and accountancy practice, helps directors meet every deadline accurately and on time. This guide explains exactly what a limited company must file, when each deadline falls in 2026/27, what the penalties are, and why accurate accounts protect you.

Key Takeaways

• A private limited company must file annual accounts with Companies House within 9 months of its accounting reference date, and a first set of accounts within 21 months of incorporation.
• The CT600 Company Tax Return must reach HMRC within 12 months of the end of the accounting period, but Corporation Tax must be paid within 9 months and 1 day of the period end.
• Companies House late filing penalties for a private company start at £150 and rise to £1,500 for accounts more than 6 months late, and double if accounts are late two years running.
• HMRC charges £100 for a CT600 filed even one day late, a further £100 at 3 months, and tax-geared penalties of 10% of unpaid tax at 6 and 12 months.
• A confirmation statement must be filed with Companies House at least once every 12 months, confirming the company's registered details, even when nothing has changed.
• Corporation Tax for 2026/27 is charged at 19% on profits up to £50,000 and 25% on profits above £250,000, with marginal relief in between.

What Must a Limited Company File Each Year?

A UK limited company must file three things each year: statutory accounts with Companies House, a CT600 Company Tax Return with HMRC, and a confirmation statement with Companies House. These are three distinct obligations submitted to two different bodies, and meeting one does not satisfy the others.

The statutory accounts report the company's financial position and are prepared under the Companies Act 2006. Small companies can usually file abridged or "filleted" accounts at Companies House, omitting the profit and loss account from the public record, while still preparing full accounts for the members and HMRC.

The CT600 is the company's tax return. It is filed with HMRC alongside the full statutory accounts and a Corporation Tax computation, and it reports taxable profit and the tax due. The confirmation statement, by contrast, carries no financial figures: it confirms registered details such as directors, shareholders, registered office, and people with significant control. All three obligations rest with the directors, who remain legally responsible even when an accountant prepares the documents.

When Are the Limited Company Filing Deadlines in 2026/27?

The key limited company filing deadlines run from two reference points: the accounting reference date (ARD) for Companies House, and the end of the accounting period for HMRC. For most companies these dates are the same, but the deadlines that follow are not.

Annual accounts must reach Companies House within 9 months of the ARD for a private company. A company with a 31 March 2026 year end therefore has an accounts deadline of 31 December 2026. A first set of accounts, covering the period from incorporation, is due within 21 months of the date of incorporation. The CT600 must reach HMRC within 12 months of the end of the accounting period, so the same 31 March 2026 year end gives a CT600 deadline of 31 March 2027.

Corporation Tax payment comes earlier than the return. Tax is due 9 months and 1 day after the end of the accounting period, meaning a company with a 31 March 2026 year end must pay by 1 January 2027, three months before the CT600 itself is due. The confirmation statement is filed at least once every 12 months, by the anniversary of the previous statement or incorporation.

The payment deadline is driven by the size of the bill, and our guide to corporation tax rates and payment dates explains how that figure is arrived at.

What Are the Penalties for Late Filing?

Late filing penalties are automatic, and they apply separately to Companies House and to HMRC, so a single late year can attract two sets of charges. There is no need for either body to prove fault; the penalty arises simply because the deadline passed.

Companies House penalties for a private company are £150 for accounts up to one month late, £375 for one to three months, £750 for three to six months, and £1,500 for more than six months. These penalties double if accounts are filed late in two consecutive years. HMRC charges £100 as soon as a CT600 is even one day late, a further £100 once it is three months late, then a tax-geared penalty of 10% of the unpaid Corporation Tax at six months and a further 10% at twelve months.

Worked example. A company with a 31 March 2026 year end owes £20,000 of Corporation Tax. It files its accounts four months late and its CT600 seven months late. Companies House charges £750, while HMRC charges £100, a further £100, and a 10% tax-geared penalty of £2,000, a total of £2,950 in penalties, on top of interest charged on the late-paid tax.

How Is Corporation Tax Calculated and Paid?

Corporation Tax is charged on a company's taxable profit, which is the accounting profit adjusted for tax purposes, and for 2026/27 the rate is 19% on profits up to £50,000 and 25% on profits above £250,000. Profits between those two thresholds are taxed at 25% with marginal relief, which gradually claws back the benefit of the lower rate.

The £50,000 and £250,000 thresholds are reduced where a company has one or more associated companies, so groups and directors with multiple companies should check the position carefully. The tax is self-assessed: the company calculates what it owes, pays by the 9 months and 1 day deadline, and reports the figure on the CT600.

Worked example. A company makes a taxable profit of £40,000 in the year to 31 March 2026. Because this is below the £50,000 lower threshold, the whole profit is taxed at 19%, giving a Corporation Tax bill of £7,600, payable by 1 January 2027. A company making £300,000 would instead pay 25% on the full amount, as it sits above the upper threshold.

Why Do Accurate Accounts Matter Beyond Compliance?

Accurate accounts matter because they are relied on far beyond the filing deadline: by HMRC when reviewing your tax, by lenders and investors assessing the company, and by you as the director making decisions. Filing on time is the minimum; filing figures that are correct is what protects the company.

Inaccurate accounts can trigger an HMRC enquiry, lead to penalties for careless or deliberate errors of up to 100% of the tax understated, and undermine a mortgage or finance application that depends on filed figures. Because small company accounts at Companies House are public, suppliers, customers, and competitors can also view them, so the public record reflects directly on the business.

Good record-keeping during the year is what makes accurate accounts possible. Maintaining clean bookkeeping, reconciling the bank, and recording dividends and director's loan movements correctly means the year-end accounts and CT600 can be prepared confidently rather than reconstructed under deadline pressure.

Frequently Asked Questions

What is the difference between filing accounts with Companies House and HMRC?

Companies House and HMRC are separate bodies requiring separate filings. Companies House receives your statutory accounts, which become part of the public record, within 9 months of your year end. HMRC receives your CT600 Company Tax Return, full accounts, and tax computation within 12 months of your accounting period end. Filing with one does not satisfy the other.

When do I have to pay Corporation Tax?

Corporation Tax must be paid 9 months and 1 day after the end of your company's accounting period, which is earlier than the CT600 filing deadline. For a 31 March 2026 year end, payment is due by 1 January 2027, while the CT600 itself is not due until 31 March 2027. Interest runs on tax paid late.

What happens if I file my company accounts late?

Filing company accounts late triggers an automatic Companies House penalty, starting at £150 for a private company up to one month late and rising to £1,500 for accounts more than six months late. Penalties double if you file late two years in a row. A late CT600 attracts separate HMRC penalties on top.

Do I still need to file a confirmation statement if nothing has changed?

Yes. A confirmation statement must be filed with Companies House at least once every 12 months even when none of your details have changed. It confirms that the registered information, including directors, shareholders, and people with significant control, remains correct. Failing to file it is a criminal offence and can lead to the company being struck off.

Can a dormant company avoid filing?

No. A dormant company must still file dormant accounts with Companies House and a confirmation statement every year. It may not need to file a CT600 if HMRC has confirmed dormant status for Corporation Tax, but it should tell HMRC it is dormant. Filing obligations continue until the company is formally closed.

How Blue Tick Can Help

Blue Tick Accountants prepares and files limited company accounts, CT600 returns, and confirmation statements for directors across the UK, making sure every deadline is met and every figure is accurate. The practice handles the full cycle from bookkeeping to final submission, so directors avoid penalties and have accounts they can rely on for lending, planning, and HMRC. If filing deadlines or Corporation Tax are weighing on you, Blue Tick can take the work off your hands. Head to our website and book a meeting now.

Conclusion

A limited company has three annual filing duties: accounts with Companies House, a CT600 with HMRC, and a confirmation statement, each with its own deadline and its own automatic penalties for lateness. The single most important action is to know your year end and diarise every resulting deadline, remembering that Corporation Tax is due before the CT600 itself. Accurate, timely filing protects you from penalties, enquiries, and reputational damage, and keeps the company in good standing.

About the Author

This guide was written by Leon, founder of Blue Tick Accountants, a Guildford-based UK tax advisory and accountancy practice that helps limited company owners, landlords, and the self-employed across the UK. It was last reviewed for the 2026/27 tax year.

This article is intended for general informational purposes only and does not constitute tax, legal, or financial advice. Tax rules are subject to change and their application will depend on your individual circumstances. You should always seek advice from a qualified professional before taking action. Blue Tick Accountants accepts no liability for decisions made on the basis of this content.