NEARLY 100,000 UK companies fall off a “first-year cliff” and file their annual accounts late, an analysis of the Companies House register of over 5 million firms has revealed — and Cardiff is the country’s latest-filing postcode.
A total of 98,151 active UK companies, or around one in every 51, have missed the legal deadline to file their annual accounts, according to the analysis by London-based accountancy firm, Zmartly.
Companies aged 18 to 24 months, the window in which a brand-new company’s first accounts fall due, are overdue at 11.73%.
That is almost one in eight new companies missing their first deadline, roughly six times the rate of firms that have been trading for a decade or more (1.46%).
The penalties escalate quickly. Companies House charges a private company £150 for accounts up to one month late, £375 for one to three months, £750 for three to six months and £1,500 beyond six months.
The penalty is doubled if a company files late in two successive years.
Cardiff (the CF postcode area) is the UK’s late-filing capital at 3.01%, ahead of North London (2.52%), the City of London (2.52%) and central London (2.47%), with Glasgow (2.38%) and Manchester (2.33%) close behind.
By sector, hospitality is the least reliable filer at 2.81%, followed by water and waste (2.80%) and education (2.46%).
At the other end, agriculture (1.42%), health and social care (1.65%) and finance and insurance (1.67%) file most reliably.
A separate finding shows the problem is wider for the simpler annual filing: 523,756 companies, around one in 10, are overdue on their confirmation statement.
Knowledge gap
Harvey Dhillon, founder of Zmartly, said: “The standout figure is the first-year cliff.
“Nearly one in eight companies aged 18 to 24 months are late with their accounts, against fewer than one in 50 established firms. In our experience, the reason is almost always a knowledge gap, not negligence.
“Founders assume the first accounts work like the second, but a company’s first accounts are due 21 months after incorporation and cover a longer-than-usual first period, so the deadline arrives sooner and bigger than people expect.”
He added: “The fix is simple, but it has to be early. Diarise the first-accounts date the day you incorporate, and get the bookkeeping going from month one rather than month 18.
“A second late year doubles the penalties, so the cost of drifting compounds fast. For most new companies this is entirely avoidable; they just need to know the date is closer than it looks.”
Matthew Knight, Chief Freelance Officer at Freelancing.Support, said setting up a business and making it a success is difficult.
He added: “There’s a huge learning curve when you’re starting a business – and no leaflet to explain all of the steps and tasks. Once you’ve done your first year’s tax return, many freelancers or small businesses sit back, thinking they’ve done what is needed, forgetting or not knowing that Companies House accounts are an additional task.
“With a variable deadline and non-standard accounting periods possible in your first year, it can be easy to get confused, and a large number of small businesses don’t have an accountant to help them out, either.”
Huge learning curve
Tony Redondo, Founder at Newquay-based Cosmos Currency Exchange, said the late filings are due to a “perfect storm”.
He added: “It’s clear that the transition to a purely software-driven, highly regulated filing system is leaving well-meaning entrepreneurs behind in the administrative dust.
“The spike in late filings stems from a perfect storm: the permanent closure of the free WebFiling portal in early 2026 forced a shift to paid commercial software, compounded by a major system outage in June that blocked submissions entirely.
“New companies are especially exposed to this ‘first-year cliff’ – first-time directors face mandatory identity verification checks and tighter accounting standards such as FRS 102, on top of the administrative overload of simply getting started.
“Many mistakenly believe dormant or inactive companies require no paperwork; others simply lose track of the 21-month initial deadline. The result is a rigid digital system that catches people unawares – with automatic penalties of up to £1,500 that double for consecutive offences.”
David Stirling, Independent Financial Adviser at Belfast-based Mint Wealth, said the system is broken.
He added: “Nearly 100,000 UK companies are filing accounts late and the government’s response is apparently to fine them rather than fix the system.
“One in eight new companies misses their first deadline, not because founders are incompetent, but because the rules are buried in small print nobody reads until the penalty letter arrives.
“Starting a company takes three minutes online, while understanding what to file and when takes three accountants and an ouija board. The Government Gateway website should have ‘Abandon all hope, ye who enter here’ plastered across the main page, as it is a hellish vortex to navigate.”
