The most common mistakes when registering a limited company in the UK are skipping identity verification, picking a name Companies House rejects, using a PO Box as the registered office, budgeting the old £50 fee (it is £100 online since February 2026), and forgetting HMRC is a separate step. Avoid these and approval usually comes within 24 hours.
Registering a limited company looks simple on paper — Companies House charges a flat fee and the whole thing usually goes through in a day. Yet a surprising number of applications get rejected, delayed, or land the founder with avoidable costs in year one. The problems are almost always the same small handful of errors. Here are the seven that matter most in 2026, and exactly how to avoid each one.
1. Leaving identity verification to the last minute
The single biggest change to company registration in recent years is the one older guides never mention: since 18 November 2025, every director and every person with significant control must verify their identity with Companies House and receive a personal code.
For a new company, each director needs their personal code before the application can be submitted — Companies House will not register an unverified director. New persons with significant control have 14 days after incorporation to supply theirs.
The mistake is treating verification as a finishing touch. With two or more directors, each verifies separately and the application waits until every code is in. Verification is free — through GOV.UK One Login with photo ID such as a biometric passport or UK driving licence, or through an authorised corporate service provider. Do it before you even open the application, and this common delay disappears entirely.
2. Choosing a company name Companies House will reject
Your name must end in “Limited” or “Ltd” (the Welsh equivalents are allowed), and it cannot be the same as — or too similar to — a name already on the register. Companies House treats some word variations as identical, so “almost different” is not different enough.
The traps founders fall into:
- Sensitive words such as “Royal”, “British”, “Bank”, “Chartered” or “Accredited” need approval and supporting evidence before Companies House will accept them.
- Names suggesting a connection with government or any public authority are refused outright.
- Offensive names, and names that imply a regulated activity you are not authorised for, get rejected too.
Check your name with the availability checker on GOV.UK before you file — and search the IPO trade mark database too. A registered trade mark holder can force you to change your company name even after Companies House accepted it.
3. Using an address that breaks the rules
Every company needs a registered office address, and the rules are stricter than people expect. It must be a physical UK address in the same part of the UK as the company (England, Scotland, Wales or Northern Ireland) — a PO Box on its own will be refused.
Here is the part founders regret later: your registered office appears on the public register. Anyone can look it up. If you used your home address, your home address is now public. This is why many founders use an accountant’s or solicitor’s address, or a registered office service, instead.
You also need a registered email address for official Companies House communication (unlike the office address, it is not published), and a service address for each director — often the registered office — so their home address stays off the public record.
4. Budgeting for the old £50 fee
Plenty of guides still quote the old prices. Ignore them. Since 1 February 2026, Companies House charges:
- £100 to register online (the standard route)
- £124 to register by post
- £156 for same-day registration through approved software
If you use a formation agent, their service fee sits on top of the £100 statutory fee — that £100 goes to Companies House either way. And while you are budgeting, remember the costs after day one: the annual confirmation statement costs £50 when filed online. Always double-check the current fee on GOV.UK’s official guide to setting up a limited company before you file, because fees and rules do change.
5. Getting the people details wrong
You need at least one director, aged 16 or over, who is not disqualified. Appointing a disqualified director is not a paperwork error — it is a serious legal offence.
Then there are people with significant control (PSCs): generally anyone holding more than 25% of the shares or voting rights, or who otherwise exercises significant influence over the company. Missing a PSC — or naming the wrong people — builds a compliance problem into your company from day one, and PSC changes must be reported within 14 days.
One misunderstanding is worth clearing up: one person can be the sole director, sole shareholder and only person with significant control. A single-founder company is perfectly normal.
6. Fumbling the shares and statement of capital
New founders overthink the share structure. Most small companies keep it simple: 100 ordinary shares at £1 each. That gives you a £100 share capital, clean paperwork, and room to issue more shares later.
The application includes a statement of capital — the number and type of shares, their total value, shareholder details, and the “prescribed particulars”: the rights attached to each share class (dividends, voting rights, redemption). Get this wrong and it is baked into your company’s founding records.
A related error is customising the articles of association without legal advice, then discovering they conflict with the memorandum. Most small businesses should simply use the government’s model articles — the standard default rules for running the company — and only deviate with professional help.
7. Thinking Companies House and HMRC are the same thing
This is the most expensive confusion in company life. Companies House maintains the public register of companies; HMRC collects tax. They are two different organisations with two different deadlines — and filing with one does not satisfy the other.
After incorporation, you must tell HMRC your company is active within 3 months of starting to trade so it can be registered for Corporation Tax. (Registering online usually handles this in the same flow.)
Then come the annual filings, in pairs:
- Annual accounts go to both. The Companies House version is public and can be abbreviated for small companies; the HMRC version goes with your company tax return and is private. The Companies House deadline is usually 9 months after the financial year end (21 months from incorporation for the first accounts). Late penalties are automatic and painful: £150 up to a month late, £375 at 1–3 months, £750 at 3–6 months, and £1,500 beyond 6 months — doubled if you are late two years running.
- The confirmation statement goes to Companies House once a year (£50 online, filed within 14 days of the end of each review period). It is not a tax return — it just confirms your company details. Not filing is an offence, and persistent failure can get your company struck off the register.
Since November 2025, your confirmation statement cannot be filed unless all directors have verified their identity — one unverified director blocks the whole filing, which is mistake number one all over again.
Get it right first time: the 5-minute pre-filing check
Before you pay the £100, run through this list: every director and PSC has their personal code; the name is unique, ends in Limited or Ltd, and has no unapproved sensitive words; the registered office is a physical UK address you are happy to make public; the share structure is simple and the PSC details are complete. Five minutes now saves weeks of rejection-and-resubmit later.
If you want the full process in order, walk through our step-by-step guide to register a limited company in the UK first — then come back here to double-check you have avoided all seven traps.
FAQ
Can I register a limited company myself?
Yes. The online service on GOV.UK is designed for private companies limited by shares using the model articles. It costs £100, usually completes within 24 hours, and most founders need no agent.
How much does it cost to register a limited company in the UK in 2026?
The Companies House fee is £100 online, £124 by post, or £156 for same-day registration through approved software. These figures apply since 1 February 2026. An agent’s service fee, if you use one, is charged on top of the statutory fee.
How long does company registration take?
Online applications are usually registered within 24 hours; postal applications take 8 to 10 days. Remember that identity verification for every director must be completed before the application can even be submitted, so build that into your timeline.
What happens if Companies House rejects my application?
Rejections are almost always fixable. Companies House tells you what is wrong — a too-similar name, an unverified director, an unacceptable address — and you correct the details and resubmit. Working through the seven mistakes above first makes a first-time approval the most likely outcome.
Conclusion
None of these mistakes is complicated — that is why they catch people out. Founders rush the exciting part, the name and the launch, and skim the administrative part. Verify identities first, choose a name and address that pass the rules, pay the current £100 fee, keep the people and share details clean, and remember HMRC is a separate job. Do that, and your company is usually up and running within a day.
