United Kingdom · Guide
A UK limited company answers to two regulators on two different calendars: Companies House, which wants your confirmation statement and accounts, and HMRC, which wants your CT600 and, before that, your money. Neither regulator reminds you of the other's deadlines, both fine you independently, and the whole calendar is rarely assembled in one place.
The stakes of reading a current source are high right now, because three numbers changed at once: the confirmation statement fee (now £50, widely listed as £34), the CT600 late penalty (now £200, widely listed as £100), and the date of the Companies House accounts reform (now 1 April 2028, widely listed as 2027). Every figure below was checked against gov.uk in August 2026.
- The short version. Each year: accounts to Companies House 9 months after your year end, corporation tax paid 9 months and 1 day after it, the CT600 filed within 12 months, and a confirmation statement within 14 days of your review period ending. Miss the accounts and penalties start at £150 and are automatic. Miss the CT600 and HMRC's meter starts at £200. The two regimes stack.
This is general information, not legal or tax advice. Figures are official gov.uk figures as of August 2026; confirm them with Companies House and HMRC before relying on them.
The UK compliance calendar at a glance
The full cycle for a private limited company, from incorporation onward:
| When | What | To whom |
|---|---|---|
| Incorporation | Company formed; your ARD (accounting reference date) is set to the last day of the incorporation month, one year on | Companies House |
| 21 months after incorporation | First annual accounts due | Companies House |
| Every year: 9 months after ARD | Annual accounts due | Companies House |
| Every year: 9 months and 1 day after the accounting period ends | Corporation tax payment due | HMRC |
| Every year: 12 months after the accounting period ends | CT600 return due | HMRC |
| Every year: review period end (12 months) + 14 days | Confirmation statement due, £50 online | Companies House |
| Ongoing | Keep registered office, registered email and officer details current; report PSC changes | Companies House |
Read the middle three rows again, because their ordering is the single most misunderstood fact in UK compliance: you pay your corporation tax before you file the return that declares it. The payment lands at 9 months and 1 day, the CT600 at 12 months, so your accounts and tax computation must exist by the 9 month mark, making the Companies House deadline and the HMRC payment date the same crunch, one day apart. And nothing is aligned by default: the accounts clock runs off your ARD, the confirmation statement off your incorporation anniversary, the tax off your accounting period. Three clocks, two regulators, zero shared reminders.
- 31 Dec 2026Accounting period ends
- 30 Sep 2027Annual accounts due at Companies House (9 months)
- 1 Oct 2027Corporation tax payment due to HMRC (9 months and 1 day)
- 31 Dec 2027CT600 return due to HMRC (12 months)
- Anniversary +14 daysConfirmation statement due, £50 online
Confirmation statement: the deadline, the £50 and what it confirms
The confirmation statement (form CS01) is the easiest filing on the list and the most casually missed, because it is due on a date unrelated to your accounts.
- What it is: a snapshot confirmation that the register's data on your company, officers, PSCs, share capital, registered office, SIC codes, is current. You are confirming, not reporting financials.
- When: at least once every 12 months. Your review period runs from incorporation (or the date of your last statement), and you have 14 days after it ends to file. That 14 day window is the tightest deadline in the whole UK calendar.
- Cost: £50 online, £110 on paper, per the Companies House fees page as updated 2 July 2026. If a guide tells you £34 or £40, it predates the fee rises; the mechanics it describes are probably still right, its prices are not.
- If you miss it: there is no automatic fine, unlike accounts, but filing is a legal duty. A company that does not file can be prosecuted and, in practice, struck off the register, which for a non-resident owner means losing the company over an unread reminder. The register also shows your statement as overdue to anyone who checks, including banks.
The confirmation statement is now also the vehicle for transitional identity verification: existing directors verify with their first statement after 18 November 2025, as covered below.
Annual accounts at Companies House: 9 months, and smaller if you are small
Every company files annual accounts, active or dormant. The deadline is 9 months after your ARD for a private company, with one first-year exception: your first accounts cover more than a year and are due 21 months after incorporation.
What you must file depends on size, and the thresholds were raised for financial years beginning on or after 6 April 2025, which a lot of older guidance has not caught up with:
| Regime | Conditions (meet 2 of 3) | What is filed at Companies House |
|---|---|---|
| Micro-entity | Turnover ≤ £1m, balance sheet ≤ £500k, ≤ 10 employees | Minimal balance sheet accounts |
| Small company | Turnover ≤ £15m, balance sheet ≤ £7.5m, ≤ 50 employees | Simpler accounts, no audit in most cases |
| Medium and large | Above small thresholds | Full accounts, audit unless exempt |
Practical translation for a typical CorpSec-formed company: you will almost certainly be a micro-entity, filing little more than a balance sheet publicly, with no audit. But do not confuse the public filing with the tax work: HMRC still requires full accounts with your CT600, however little Companies House displays. The abridged and filleted options survive until the 2028 reform below.
Corporation tax: pay in 9 months and 1 day, file the CT600 in 12
The HMRC half of the calendar, compressed to what matters:
- Payment: 9 months and 1 day after the end of your accounting period. Interest runs on late payment from the due date.
- CT600: 12 months after the end of the accounting period, filed online with accounts and computations attached.
- Yes, in that order. The tax is due before the return. Companies that treat the 12 month filing date as "the deadline" discover the payment deadline retroactively, with interest.
One first-year quirk to expect: a company incorporated mid-month usually has a first accounting period longer than 12 months, which HMRC splits into two accounting periods, a 12 month one and a short one, each with its own CT600 and its own payment date. It looks like an error; it is normal, and it is one more reason first-year compliance deserves adult supervision.
The rates and the marginal relief math behind the payment live in the corporation tax guide; what happens to non-resident owners when the profit comes out lives in the non-resident tax guide.
Late filing penalties: two regulators, two meters
This is where the two-calendar structure gets expensive, because the penalty regimes are independent and cumulative. Both tables below are the figures in force as of August 2026.
Companies House, late accounts (automatic, no discretion):
| How late | Penalty (private company) |
|---|---|
| Up to 1 month | £150 |
| 1 to 3 months | £375 |
| 3 to 6 months | £750 |
| Over 6 months | £1,500 |
File late two years in a row and the penalty for the second year doubles, so a repeat 6 month slip costs £3,000. These are civil penalties issued automatically on filing; appeals succeed only in genuinely exceptional circumstances.
HMRC, late CT600 (doubled from 1 April 2026; older figures are still widely quoted):
| How late | Penalty |
|---|---|
| 1 day | £200 |
| 3 months | another £200 |
| 6 months | 10% of the unpaid tax (HMRC estimates it) |
| 12 months | another 10% |
File late three accounting periods in a row and the flat £200 penalties become £1,000 each. Late payment accrues interest separately, on top of everything above.
Stack the meters for one badly missed year end: accounts 7 months late (£1,500) plus a CT600 6 months late (£400 plus 10% of the tax) is north of £2,000 before interest, on a company that may have earned nothing that year.
Identity verification and the new Companies House rules
The ECCTA reforms turned Companies House from a passive register into a verifier, on a rolling timetable that matters to anyone forming or running a company now:
- Identity verification (IDV) is mandatory since 18 November 2025. New directors must verify before appointment; existing directors verify with their company's next confirmation statement during a 12 month transition; PSCs verify within 14 days of their birth month window. Verification runs through GOV.UK One Login or an authorised agent (ACSP), and produces a personal code you reuse across companies.
- The non-resident angle, which the UK-domestic guides skip: verification is designed to work fully online with a biometric passport via the One Login app, so a founder abroad can generally verify without visiting the UK; where the app route fails, verification through an ACSP, such as your formation agent, is the fallback. Build IDV into your incorporation timeline rather than discovering it at filing time; the step-by-step is in the registration guide.
- A registered email address is now required for all companies, collected from existing companies via the confirmation statement, and Companies House uses it for statutory communication. For an owner 10,000 km from the registered office, this inbox is effectively your compliance lifeline; keep it monitored.
What changes on 1 April 2028 (not 2027)
The biggest future change to UK accounts filing has moved, and most of the internet has not noticed. The ECCTA accounts reform, originally trailed for April 2027, is now scheduled for 1 April 2028:
- Software-only filing. Accounts will have to be filed through commercial software; the WebFiling and paper routes close.
- End of abridged and filleted accounts. Small companies and micro-entities will file their profit and loss account, ending the era of the balance-sheet-only public filing.
- Practical consequence for founders who chose the UK partly for modest disclosure: from the 2028 filings onward, your small company's P&L becomes part of the public record (subject to any final carve-outs), and your accountant's software choice becomes a compliance dependency.
If a page tells you this is happening in 2027, that is your freshness test: the postponement to 1 April 2028 was announced by Companies House in 2026. Nothing changes about deadlines or penalties before then.
What a UK company does NOT have to do
Founders arriving from heavier regimes budget for ghosts, so the absences are worth stating:
- No audit below the small company thresholds, which covers the overwhelming majority of founder-owned companies.
- No AGM requirement for a private limited company unless its articles insist.
- No P&L on the public record for micro-entities and small companies, until the 1 April 2028 reform.
- No flat annual state tax: unlike Delaware's $400, the UK charges only the £50 confirmation statement fee as a recurring registry cost.
- Dormant companies file simplified dormant accounts, and with HMRC's agreement can skip CT600s while dormant.
For readers weighing jurisdictions, the standing comparison with the other two default picks:
| Yearly obligation | UK Ltd | Delaware LLC | Estonia OÜ |
|---|---|---|---|
| Registry filing | Confirmation statement, £50 | None | Annual report, mandatory |
| Accounts filed and public | Yes (minimal if micro, until 2028) | No | Yes |
| Flat state fee | No | $400 tax, June 1 | No |
| Audit | No, below thresholds | Never | Only above thresholds |
The structural trade: more paperwork than Delaware, less secrecy than founders expect, in exchange for low fees and a first-tier commercial reputation. The Delaware column is unpacked in the Delaware compliance guide; the full UK cost picture is in the cost guide.
Dormant companies and your first year
Two situations produce the most missed deadlines per capita:
- Dormant companies. "Dormant" means different things to the two regulators: Companies House cares about significant accounting transactions (roughly none), HMRC cares about whether you are active for corporation tax. A company can be dormant for HMRC and still owe Companies House dormant accounts and a confirmation statement every year. Dormancy shrinks the filings; it never ends them, and the £150 accounts penalty applies to a dormant company exactly as to a trading one.
- The first year. Everything is irregular once: first accounts at 21 months, a first accounting period often split into two CT600s, a first confirmation statement at 12 months plus 14 days, with IDV now woven in. Most penalties are earned in year one, not year five, because no annual rhythm exists yet.
The bottom line
UK compliance is not heavy, but it is plural: two regulators, three clocks, penalty meters that start automatically and stack. It all compresses into four dates hung off two anchors, your ARD and your incorporation anniversary; put them in a calendar with the 9 month crunch flagged in red and the whole system costs £50 a year.
If you would rather have the calendar, the filings, the registered email and the IDV steps owned by someone accountable, that is exactly what the UK company package exists to absorb; a specialist can also map your first irregular year before the deadlines start moving.
Frequently asked questions
What must a UK company file every year?
Annual accounts to Companies House (9 months after year end), a corporation tax payment (9 months and 1 day), a CT600 to HMRC (12 months), and a confirmation statement (within 14 days of each 12 month review period). Dormant companies still file accounts and the confirmation statement.
When is the confirmation statement due and how much does it cost?
Within 14 days of the end of each 12 month review period, which starts at incorporation or your last statement. £50 filed online, £110 on paper, as of the gov.uk fees update of July 2026. Pages quoting £34 or £40 are out of date.
What happens if my accounts are late?
An automatic Companies House penalty: £150 up to 1 month late, £375 to 3 months, £750 to 6 months, £1,500 beyond, doubled if you were also late the previous year. There is no discretion and appeals rarely succeed.
Are Companies House and HMRC penalties separate?
Completely. Late accounts and a late CT600 are fined independently, and interest on late paid tax runs on top. One badly missed year end typically costs over £2,000 across the two regimes.
When is corporation tax actually due?
9 months and 1 day after your accounting period ends, which is before the CT600 filing deadline at 12 months. You pay first, file after; treat the 9 month date as the actual deadline.
Do micro-entities have to file a profit and loss account?
Publicly, not yet: a micro-entity files little more than a balance sheet at Companies House. That changes with the reform of 1 April 2028, when small companies and micro-entities file their P&L under software-only filing. HMRC already requires full accounts with the CT600 today.
Is an audit required?
Not for most founder-owned companies. Small companies (up to £15m turnover, £7.5m balance sheet, 50 employees, 2 of 3) are generally audit exempt, and micro-entities even more so.
What is identity verification and does it work from abroad?
Since 18 November 2025, directors and PSCs must verify their identity with Companies House, via GOV.UK One Login or an authorised agent. New directors verify before appointment; existing ones with their next confirmation statement. It is designed to work fully online with a biometric passport, so non-residents can normally verify without visiting the UK.
When does software-only accounts filing start?
1 April 2028, postponed from the originally trailed April 2027. From then, accounts must be filed through commercial software and abridged accounts end.
My company made no money. Do I still file?
Yes, everything: accounts (dormant accounts if eligible), the confirmation statement, and a CT600 unless HMRC has agreed the company is dormant for corporation tax. Zero activity reduces the content of the filings, not their deadlines or penalties.
Sources
- Companies House: prepare and file annual accounts for a private limited company
- Companies House: confirmation statement guidance and fees
- Companies House: late filing penalties for accounts
- HMRC: Company Tax Returns, deadlines and penalties
- Companies House: changes to UK company law (ECCTA rollout, identity verification)
All fees, deadlines and penalty figures were checked against gov.uk and the Companies House ECCTA campaign site in August 2026, including the £50 confirmation statement fee (gov.uk fees page updated July 2026), the CT600 penalties doubled from 1 April 2026, and the accounts reform postponed to 1 April 2028. Several older figures (£34 fees, £100 penalties, a 2027 reform date) still circulate widely; where this guide differs from other pages, gov.uk is the reference. Confirm current figures with Companies House and HMRC before relying on them.