Companies House Deadlines 2026: When Accounts & Confirmation Statements Are Due (and What Late Costs You)

Every UK limited company has two recurring filing obligations with Companies House: annual accounts and a confirmation statement. Miss either deadline and the company starts racking up automatic penalties, with strike-off proceedings beginning around six months past due.

For accountants, bookkeepers and company secretarial services, those deadlines are the most reliable buying signal in the UK B2B market. Companies looking down the barrel of a missed accounts deadline are *actively* shopping for a fix.

This post explains the rules and then shows how to turn them into a prospecting workflow.

Annual accounts, the 9-month rule

A private limited company in the UK must file its annual accounts with Companies House within 9 months of its accounting reference date (ARD). The ARD is the last day of the company's financial year. By default, when a company incorporates, Companies House sets the ARD to the last day of the month one year after incorporation.

So if a company incorporates on 14 March 2025, its first ARD is 31 March 2026, and its first accounts are due by 31 December 2026.

A few quirks:

• First-year accounts are slightly different, they cover from incorporation up to the ARD, so the deadline is 21 months from incorporation rather than 9 months from the ARD.
• Public limited companies have only 6 months, not 9.
• Changing the ARD moves the deadline. Companies do this to align with a parent company's year end or to buy time.
• Late filing penalties start at £150 for being one day late and climb to £1,500 for being more than 6 months late, doubling if the company is late two years running.

Confirmation statements, the 14-day rule

The confirmation statement (form CS01) replaced the old annual return in 2016. Every UK company must file at least one every 12 months, confirming that the registered office, directors, shareholders, PSCs and SIC codes Companies House holds are correct.

The 12-month "review period" starts on the company's incorporation date or the date of the last confirmation statement, whichever is later. The statement itself is then due within 14 days of the end of that review period.

Practical implication: a company incorporated on 1 February 2025 has a confirmation statement due by 15 February 2026, and another due by 15 February 2027, and so on every year.

If a company misses the confirmation statement deadline, Companies House can, and increasingly does, start strike-off proceedings within a few months. Unlike late accounts, there is no automatic financial penalty, but the directors can be prosecuted personally.

Why these dates are gold for accountants

Two reasons:

1. They are forced buying moments. A company without an accountant who is 60 days from an accounts deadline has a real, immediate, deadline-driven problem to solve. Conversion rates on outbound at this point are dramatically higher than to a "cold" prospect.
2. They are completely public. Companies House publishes the next-due date for every company, every day, in machine-readable form. You don't need to guess.

The accountant prospecting workflow

The playbook our accountant customers use is:

1. Pull a list of UK Ltd companies whose accounts are due in the next 30–90 days. Filter by region if you serve locally. Filter out companies that already have a recently-changed accountant (look for a Filing History entry mentioning AA01 or a recent professional firm address change).
2. Enrich each one with a website and a named director email. Use our guide to SIC code prospecting for the data side.
3. Send a personalised first-touch email referencing the deadline and offering a fixed-fee, deadline-rescue package. A dated, specific reason to write beats a generic introduction, because the recipient can check it.
4. Let it run every morning. New companies cross into the 30-90 day window every single day. A Leadistry agent reads the public record each morning and puts the new matches in the Feed, each with the first email already drafted. You approve, it sends from your own mailbox, two short follow-ups go out, and a reply stops everything to that company.

Work out your own version before you commit the time: take the number of companies with a deadline in your patch each week, and apply whatever reply and conversion rate your own past outreach has actually produced. Anyone quoting you an industry reply rate is describing their list and their offer, not yours.

Confirmation statements as a softer signal

Confirmation statements are less urgent (no auto-penalty, just strike-off risk) but useful for secretarial services, company law firms and virtual office providers. A company about to file its first or second confirmation statement is often re-evaluating its registered office address, its PSC structure, or whether it needs Companies Act compliance support.

What about charges and changes?

Annual accounts and confirmation statements are the two predictable, scheduled deadlines. Companies House also tracks event-driven filings, new charges (mortgages and debentures), director changes, address changes, share allotments. Each of those is its own buying signal, but they're not deadline-driven, so the urgency angle doesn't apply.

We cover those event-driven signals separately in our SIC code playbook.

Bottom line

If you sell anything related to compliance, finance, payroll, tax or company secretarial work, the Companies House deadline calendar is the single most reliable prospecting feed in the UK. Build your workflow around it and the rest of outbound becomes easier.