Two Separate Filing Requirements Every Director Must Know
Running a UK limited company creates two distinct annual filing obligations that many first-time directors confuse or conflate. They cover the same accounting period but go to different organisations, have different formats, and carry different penalties:
- Companies House: Receives your statutory annual accounts. These are a formal financial statement of the company's position. They become publicly visible on the Companies House register — any member of the public can look up your company's accounts for free.
- HMRC: Receives your Corporation Tax return (the CT600 form) along with a full tax computation. This is a private filing — HMRC does not share your tax computation with Companies House or the public.
Both filings are mandatory, both have strict deadlines, and the penalties for missing them are automatic. There is no grace period and no requirement for HMRC to send a reminder. The deadlines are calculated from your company's financial year end — which may not be 31 March or 5 April.
Companies House Annual Accounts — What They Include
The format and content of your statutory accounts depend on the size of your company. Most first-year limited companies qualify as micro-entities or small companies:
Micro-entity (must meet at least 2 of 3 criteria: turnover below £632,000, balance sheet below £316,000, 10 or fewer employees):
- Balance sheet only — no requirement to file a profit and loss account or director's report at Companies House (though both must still be prepared for HMRC)
- A director's statement confirming the company qualifies as a micro-entity
- No auditor's report required
Small company (must meet at least 2 of 3 criteria: turnover below £10.2m, balance sheet below £5.1m, 50 or fewer employees):
- Balance sheet plus notes to the accounts
- Director's report
- Option to file abridged accounts (omitting the profit and loss from the public register)
- No audit required unless the company is part of a group or has specific regulatory requirements
Larger companies require full statutory accounts including an auditor's report — but these are a small minority of UK limited companies. For most sole-director consultants, contractors, and small business owners, micro-entity or small company accounts apply.
All accounts must be filed in iXBRL format (inline XBRL) — a digital tagging standard that allows Companies House and HMRC to extract data automatically. Paper accounts are no longer accepted for most companies. This requirement means accounts must be prepared using compatible software, not just a word-processed document.
The CT600 Corporation Tax Return to HMRC
The CT600 is the main Corporation Tax return form. It is submitted to HMRC together with:
- A full set of statutory accounts (profit and loss, balance sheet, notes) — even if the Companies House filing is a simplified micro-entity version
- A detailed tax computation showing how taxable profits were derived from accounting profits — including any adjustments for disallowable expenses, capital allowances claimed, director loan interest, and any other items that are treated differently for tax than for accounting
The CT600 also captures any losses carried forward or back, group relief (where applicable), R&D tax credits, and capital gains. For straightforward single-director companies with only trading income, the computation is relatively simple — but it must be prepared correctly and filed in iXBRL format.
Corporation Tax rates in the UK as of April 2023:
- 19% on profits up to £50,000 (small profits rate)
- 25% on profits above £250,000 (main rate)
- Marginal relief applies on profits between £50,000 and £250,000, with the effective rate scaling from 19% to 25%
The tax computation must show which rate applies, or how marginal relief is calculated if profits fall in the tapered band. An error in this calculation can result in underpayment with interest, or an overpayment that must be reclaimed from HMRC.
All Deadlines in One Place
| Filing | Recipient | Deadline | Penalty for being late |
|---|---|---|---|
| Annual accounts | Companies House | 9 months after financial year end | £150 (up to 1 month) · £375 (1–3 months) · £750 (3–6 months) · £1,500 (6+ months) — doubled if late two years running |
| CT600 Corporation Tax return | HMRC | 12 months after accounting period end | £100 fixed · £200 after 3 months · 10% of unpaid tax after 18 months |
| Corporation Tax payment | HMRC | 9 months and 1 day after accounting period end | Interest from day 1 after deadline at HMRC late payment rate |
| Confirmation statement (annual return) | Companies House | Within 14 days of each anniversary of incorporation | Strike-off action if persistently unfiled |
Note the sequencing: Corporation Tax must be paid (9 months + 1 day) before the CT600 is due (12 months). This catches many first-time directors off guard — the tax is due before the formal return is filed.
What First-Year Directors Need to Know
The first year of running a limited company involves several steps that experienced accountants know by default but that are not obvious to new directors:
- Register for Corporation Tax within 3 months of starting business. Do this through HMRC Online Services. If you miss this deadline, HMRC can issue a penalty. Your company's UTR arrives by post within a few weeks.
- Your accounting reference date (ARD) is automatic. Companies House sets it as the last day of the month in which your company was incorporated. If you incorporated on 14 March, your ARD is 31 March. Your first accounts cover the period from incorporation to 31 March of the following year — which may be less than 12 months.
- First accounts are due 21 months after incorporation, not 9 months. This is the only time the 21-month rule applies — from the second year onward, the deadline is 9 months from year end.
- Director salary vs dividends. Most small company directors take a combination of salary (taxed as employment income) and dividends (taxed at dividend rates, which are lower than Income Tax for basic-rate taxpayers). The split needs to be correct for the accounts and for the director's personal Self Assessment return. An Indian CA firm can advise on the optimal split based on current rates.
- Director loans. If you take money from the company account for personal use and it is not salary or dividend, it is treated as a director's loan. Overdrawn director loan accounts carry Corporation Tax charges (Section 455 tax) if not repaid within 9 months of the year end.
How an Indian CA Firm Prepares Your Annual Accounts
The process for outsourcing limited company accounts to an Indian CA firm is fully remote and typically takes 10–15 working days from receiving complete records:
- Provide your bookkeeping records. Share your year-end bookkeeping file (Xero, QuickBooks, or bank statements if you have no software), sales invoices, purchase invoices, payroll summary, any hire purchase or loan agreements, and asset purchase details for capital allowance claims. If we handle your monthly bookkeeping, the year-end records are already prepared.
- Prepare statutory accounts. The firm prepares a balance sheet, profit and loss account, director's report, and notes to accounts in the correct format for your company size. These form the basis for both the Companies House filing and the HMRC submission.
- Prepare the Corporation Tax computation. The accounting profit is adjusted for tax purposes — disallowable expenses removed, capital allowances added, director loan adjustments applied. The applicable Corporation Tax rate is confirmed and the liability calculated.
- iXBRL tagging. The accounts and computation are tagged in iXBRL format using compliant software, ready for electronic submission to both Companies House and HMRC.
- Director review and approval. You review a plain-language summary of the accounts, tax liability, payment due date, and any items requiring your attention. Nothing is filed without your sign-off.
- Electronic filing. The CT600 and full accounts are submitted to HMRC via their online portal. The abbreviated accounts are filed at Companies House. Both filings are confirmed and you receive electronic acknowledgements.
For UK limited companies needing ongoing support beyond the annual accounts, our monthly bookkeeping and Virtual CFO service keeps your books current throughout the year and makes the annual accounts preparation significantly faster. For more detail on the year-end process, see our guide to outsourcing year-end accounts preparation to India.
Limited companies with employees also need monthly payroll and quarterly accounts payable reconciliation. These are all handled remotely from our ICAI-registered practice at a fraction of the cost of a UK accountancy firm. Explore the full scope of what we offer for UK businesses.
Written by Sharma Jyoti, CA (ICAI) — Founder, Sharma Jyoti and Co. We are an ICAI-registered Chartered Accountant firm providing outsourced bookkeeping and accounting services to Australian, US, UK and Canadian businesses. Learn more about our firm →
Frequently Asked Questions
Annual accounts must be filed at Companies House within 9 months of your company's financial year end. For a new company, accounts for the first period are due within 21 months of the date of incorporation. A CT600 Corporation Tax return must be submitted to HMRC within 12 months of the end of the accounting period, and Corporation Tax must be paid within 9 months and 1 day of the accounting period end — before the CT600 is due.
Companies House receives your statutory accounts — a formal financial report including a balance sheet, profit and loss account, and director's report. These are publicly visible on the Companies House register. HMRC receives your CT600 Corporation Tax return along with a full tax computation showing how you calculated your Corporation Tax liability. The two filings cover the same period but are different documents submitted to different organisations.
A local UK accountancy practice typically charges £600–£2,000 per year to prepare and file limited company accounts and the CT600, depending on complexity. An Indian CA firm provides the same service for £150–£400 per year — a saving of £400–£1,600 annually. The accounts are prepared in iXBRL format and filed electronically to both Companies House and HMRC.
Companies House charges automatic late filing penalties: £150 for up to 1 month late, £375 for 1–3 months, £750 for 3–6 months, and £1,500 for over 6 months late. These penalties double if accounts are late in two consecutive years. HMRC charges a separate £100 penalty for a late CT600, rising to £200 after 3 months, and interest on any Corporation Tax paid after the 9-month-plus-one-day deadline.
Yes. A newly incorporated company's accounting period can be extended. You can lengthen your first accounting reference date by up to 18 months, giving you up to 21 months from incorporation to file first accounts at Companies House. This is useful if you incorporate mid-year and want your first accounting period to align with a calendar year or a natural business cycle. Changes to the accounting reference date are filed via Companies House.