A year-end accounting deadline is the last legal date for delivering annual accounts to Companies House and paying Corporation Tax to HMRC. Directors of small UK limited companies manage 2 linked dates after every accounting period: payment 9 months and 1 day after the period ends, and accounts delivery within 9 months of the accounting reference date. Penalties start at £150, reach £1,500, and double on a second consecutive late year.
This guide sets out the limited company accounting deadlines that follow every company year end, a 6-task preparation list, and the full penalty table. GOV.UK publishes the rules; this page converts them into a working diary for directors.
What Is a Year-End Accounting Deadline?
A year-end accounting deadline is the statutory date by which a limited company is required to deliver its annual accounts to Companies House and settle its Corporation Tax charge with HMRC. The deadline attaches to the accounting reference period, normally 12 months, which ends on the accounting reference date. Companies House fixes that date at incorporation as the last day of the month of incorporation, so a company incorporated on 14 March holds a 31 March year end.
Two regulators run two separate clocks from that date:
- Companies House requires annual accounts delivered within 9 months of the end of the accounting reference period for private limited companies and LLPs, and within 6 months for public companies.
- HMRC requires Corporation Tax paid 9 months and 1 day after the end of the accounting period, and the CT600 Company Tax Return filed within 12 months.
Directors carry personal responsibility for delivery, and delivery means actual receipt at Companies House in the correct format. Accounts posted on the final day that arrive late count as late. Directors who outsource company accounts preparation keep the statutory duty regardless, because company law attaches it to the office of director, not to any agent.
Which Deadlines Apply to a Limited Company?
A limited company works to 3 statutory deadlines after each accounting period ends: the Corporation Tax payment at 9 months and 1 day, the annual accounts filing within 9 months, and the CT600 Company Tax Return within 12 months.
Accounts delivery to Companies House. Private limited companies and LLPs file accounts with Companies House within 9 months of the end of the accounting reference period. Public companies file within 6 months. A company with a 31 December year end therefore delivers its accounts by 30 September the following year.
First accounts. First accounts covering more than 12 months are due within 21 months of incorporation for private companies, or within 3 months of the accounting reference date, whichever period is longer. Public companies file first accounts within 18 months of incorporation. The extended window applies once; every later year runs on the standard 9-month cycle.
Corporation Tax payment. Companies with taxable profits up to £1.5 million settle their Corporation Tax bill 9 months and 1 day after the end of the accounting period. Companies with profits above £1.5 million pay by quarterly instalments instead, with instalment dates set by HMRC against the accounting period. A 31 March year end makes the payment due on 1 January.
Company Tax Return. The CT600 return reaches HMRC within 12 months of the end of the accounting period. Late filing penalties apply to the CT600 even where no tax is payable, so an inactive year does not pause the clock.
The pair to diarise. Diarise 2 dates for every accounting period: the accounts filing date at 9 months and the payment date at 9 months and 1 day. For a 31 December year end, accounts arrive by 30 September and tax by 1 October, one day apart.
How Should You Prepare for Year End?
To prepare for year end, directors complete 6 tasks before the accounting reference date arrives. Companies that maintain monthly management accounts start this list with figures already reconciled, which shortens preparation time. Companies reconciling for the first time allow several weeks.
- Reconcile every account. Bank accounts, loans, credit cards, and payment platforms reconcile to statements dated the accounting reference date, so every closing balance is proven.
- Collect the missing paperwork. Sales invoices, purchase receipts, payroll reports, dividend vouchers, and mileage logs gathered by month 10 prevent delays at the filing stage.
- Review the debtor and creditor ledgers. Aged balances identify bad debt provisions and unrecorded supplier invoices before the accountant raises queries.
- Check the fixed asset register. Additions, disposals, and depreciation rates reconcile to the general ledger, and obsolete assets are written off or flagged.
- Diarise both statutory dates. Count 9 months forward from the accounting reference date for filing, and 9 months and 1 day for payment, and set reminders 3 months ahead of each.
- Brief your accountant early. Records delivered a quarter before the deadline leave room for questions, adjustments, and tax planning; records delivered in the final fortnight leave none.
Preparation protects more than the penalty position. Reconciled records produce accurate profit figures, and accurate profit figures set the payment amount due at 9 months and 1 day. Directors who prepare early also gain time to reserve cash for the liability rather than borrowing at the deadline.
What Happens If You Miss Your Year-End Deadline?
Missing your year-end deadline costs an automatic Companies House penalty between £150 and £1,500, doubled on a second consecutive late year, plus HMRC penalties on any late tax return.
The table below lists the Companies House late filing penalty by delay band for private limited companies and LLPs, with the higher public company rates alongside for comparison.
| Accounts filed late by | Private company / LLP | Public company |
|---|---|---|
| 1 month or less | £150 | £750 |
| More than 1 month, up to 3 months | £375 | £1,500 |
| More than 3 months, up to 6 months | £750 | £3,000 |
| More than 6 months | £1,500 | £7,500 |
The company, not the accountant, pays the penalty, and each band doubles where accounts are filed late in 2 successive financial years. A private company that repeats a 4-month delay therefore pays £1,500 the second time.
Criminal exposure. Failing to deliver accounts or confirmation statements is a criminal offence. Directors face personal fines, and the Registrar of Companies can strike the company off the register, which removes its legal existence.
HMRC penalties. Late CT600 filing attracts penalties even where the company owes no tax. A company that paid its Corporation Tax in full still pays a filing penalty when the return is late, so the 12-month return deadline merits its own diary entry.
Common Questions Answered
These 4 questions cover the deadline facts directors ask about most.
When do I need to file my company accounts?
Established private limited companies file accounts within 9 months of the end of the accounting reference period. First accounts covering more than 12 months fall due within 21 months of incorporation. Public companies file within 6 months of the period end, or 18 months of incorporation for first accounts.
What is the Corporation Tax payment deadline?
The Corporation Tax payment deadline is 9 months and 1 day after the end of the accounting period for companies with taxable profits up to £1.5 million. Companies above £1.5 million pay quarterly instalments. The CT600 return is due 12 months after the period ends, whatever the profit level.
How much is the Companies House late filing penalty?
The penalty is £150 for accounts up to 1 month late, £375 for 1 to 3 months, £750 for 3 to 6 months, and £1,500 beyond 6 months. Each penalty doubles if accounts are filed late in 2 successive financial years.
Does my accountant or Companies House track these deadlines for me?
Companies House sends email reminders to directors who sign up, yet legal responsibility stays with the directors. Filing late remains a director’s offence even where an adviser misses the date. Diarise both deadlines yourself and confirm receipt of filed accounts.
How Aqua Accounting Can Help
The Aqua Accounting team manages year-end accounts, Corporation Tax compliance, and monthly reporting for limited companies across the North East. The firm is an ICAEW Registered Member Firm, and its UK-based team of Chartered Accountants brings 13+ years serving North East businesses from Newcastle upon Tyne.
Every engagement opens with a deadline map: your accounting reference date, the filing date 9 months later, the payment date at 9 months and 1 day, and the CT600 date at 12 months. You see every date once, in one place, before the period closes.
Book a year-end review and both dates on your year-end accounting deadline calendar stay protected, penalty-free, from the first month of the period.
Disclaimer:
The information provided in this blog is for general informational purposes only and does not constitute professional advice. While every effort is made to ensure accuracy, Aqua Accounting accepts no responsibility for any actions taken based on this content. You should seek professional advice tailored to your individual circumstances.
Omar Ahmed is an ICAEW Chartered Accountant and the Director of Aqua Accounting, a UK-based accountancy practice providing expert accounting and tax services to individuals, sole traders, and small to medium-sized businesses. As a trusted accountant in Newcastle, he offers expertise in annual accounts, self-assessment tax returns, company accounts, VAT, payroll, bookkeeping, and company formation.
With a strong focus on delivering clear and practical financial advice, Omar helps clients stay compliant while improving their understanding of their finances. Through Aqua Accounting, he works closely with business owners to simplify accounting processes, meet tax obligations, and support informed financial decision-making.