Most online applications are approved by Companies House within 24 hours, yet the compliance clock starts the moment incorporation is confirmed. From April 2026, a Company Tax Return filed even one day late carries a fixed £200 penalty from HMRC.
In this blog, we discuss what happens in the first 90 days after setting up business in the UK. We cover the documents to secure and the HMRC registrations to complete. We also flag the compliance steps many founders overlook, and the first-year deadlines that matter most.
What Are the First Steps After Setting Up a Company in the United Kingdom?
Secure the Certificate of Incorporation and authentication code in week one, and track the Unique Taxpayer Reference, which normally arrives within a couple of weeks.
Approval from Companies House is only the beginning. In practice, the first week after setting up business in the UK determines how smoothly every later filing goes. Companies House, HMRC and UK banks do not necessarily require identical items, but these three documents sit behind most early requests.
We help clients secure these items as part of our United Kingdom company incorporation services. We routinely see delays when any one of them goes missing. The steps below should be completed before routine trading begins.
1. Store Your Certificate of Incorporation
The certificate confirms the company's legal existence and provides its Company Registration Number. It usually arrives by email and is a standard requirement for opening a business bank account.
2. Keep Your Authentication Code Safe
Companies House posts an authentication code to the registered office a few days after incorporation. This code is needed for almost every online filing, so it should be stored securely from day one.
3. Track Your Unique Taxpayer Reference
HMRC normally issues a Unique Taxpayer Reference (UTR) to the registered office within a couple of weeks of incorporation. Corporation Tax registration, notifying HMRC that trading has begun, is the separate action founders must take.
4. Open a UK Business Bank Account
Most UK banks require the certificate of incorporation and proof of directors' identity. A separate company account is good governance rather than a universal statutory requirement, but it keeps personal and company finances distinct and simplifies record-keeping.
When Must You Register for Corporation Tax and VAT?
HMRC requires Corporation Tax registration within three months of starting to trade, and VAT registration once taxable turnover passes £90,000.
According to HMRC, a new company must register for Corporation Tax within three months of starting to trade. In practice, 'starting to trade' usually means the first invoice, the first deposit taken, or the first contract signed.
Registration is done through a business tax account on GOV.UK using the UTR. HMRC then sets the accounting period that governs all later tax deadlines.
1. Register for Corporation Tax Promptly
Missing the three-month window exposes the company to a 'failure to notify' penalty, which applies separately from any late-filing penalty on the return itself.
2. Check the £90,000 VAT Registration Threshold
Businesses must register for VAT once taxable turnover exceeds £90,000 in any rolling 12-month period, or is expected to within the next 30 days alone. Voluntary registration can also suit companies with significant input VAT.
3. Set Up PAYE Before the First Payroll Run
Any company employing staff, or paying director salaries, must register for Pay As You Earn (PAYE) before the first payroll run. This is separate from both Corporation Tax and VAT registrations.
First 90 Days: Key Tasks and Deadlines
| Timeframe | Task | Why It Matters |
|---|---|---|
| Week 1 | Store certificate, authentication code and UTR | Required for online filings and bank account opening |
| Week 1–4 | Open a UK business bank account | Separates company and personal finances |
| Within 3 months of trading | Register for Corporation Tax with HMRC | Avoids 'failure to notify' penalties |
| Before first payroll | Register for PAYE | Legally required for salaries and employees |
| Any rolling 12 months | Register for VAT at £90,000 turnover | Legal obligation once threshold is crossed |
| First 90 days | Pay ICO fee and complete PSC verification | Mandatory under UK GDPR and ECTA 2023 |
What Other Compliance Steps Come After Registering a Company in the UK?
Most new companies must pay the ICO data-protection fee unless exempt, complete PSC verification as the phased identity-verification timetable applies, and check whether their sector needs a licence.
Beyond HMRC, several less-publicised duties fall due in the first 90 days. Companies House rules state that company records — directors, shareholders, registered office and PSC details — must be accurate at all times, not only at annual filing.
Avoiding common UK company formation mistakes at this stage is far cheaper than correcting them later. The three steps below cover the duties founders most often miss.
1. Pay the ICO Data-Protection Fee
Most companies processing personal data must pay the Information Commissioner's Office (ICO) data-protection fee, unless they qualify for an exemption. They should also begin documenting data-processing activities under UK GDPR.
2. Complete PSC Identity Verification
Under the Economic Crime and Corporate Transparency Act 2023, every Person with Significant Control must be verified. The identity-verification requirement is being phased in, so timing depends on the company's filing route. Full name, date of birth, nationality and nature of control go into the PSC register.
3. Check Sector-Specific Authorisations
Fintech, healthcare, food and crypto businesses typically need Financial Conduct Authority (FCA) or another regulator's sign-off before launch. Trading without the required licence can attract penalties or criminal sanction.
Which First-Year Deadlines Start Ticking Immediately?
Three annual filings matter most in year one: the confirmation statement, the annual accounts, and the Corporation Tax return.
Companies House fees and HMRC penalties have both risen for 2026, so missing dates is now materially more expensive. The confirmation statement fee is £50 online and £110 on paper from 1 February 2026.
Late accounts penalties start at £150 and reach £1,500 after six months, doubling if filed late two years running. The Corporation Tax deadlines also run on two separate clocks, which catches many first-time founders.
1. Confirmation Statement
The first confirmation statement falls due 12 months after incorporation, confirming the public record for directors, shareholders, the registered office and PSCs. It must be filed within 14 days of the review date.
2. Annual Accounts
A private company's first accounts are due 21 months after incorporation. After year one, accounts are due nine months after each accounting period ends.
3. Corporation Tax Payment and CT600
Tax is payable nine months and one day after the accounting period ends, while the CT600 return is due 12 months after it ends. From 1 April 2026, a CT600 filed one day late incurs a fixed £200 penalty, rising to £400 beyond three months, plus surcharges at six and twelve months.
First-Year Filing Deadlines and Penalties
| Filing | Due Date | Late Penalty Risk |
|---|---|---|
| Confirmation statement | 12 months after incorporation, 14 days to file | £50 online fee from 1 February 2026 |
| First annual accounts | 21 months after incorporation | £150 to £1,500, doubling if late two years running |
| Corporation Tax payment | 9 months and 1 day after period end | Interest on unpaid tax |
| CT600 return | 12 months after period end | £200 one day late; £400 over 3 months, plus surcharges, from 1 April 2026 |
Can You Manage UK Company Obligations From Overseas?
Yes — non-resident directors can run a UK company, provided the company keeps a UK registered office and meets every filing deadline.
Operating a UK company from abroad is entirely lawful, but distance makes deadlines easier to miss. Every HMRC and Companies House obligation described above applies equally regardless of where the directors live.
A UK registered office address is mandatory, and official correspondence from Companies House and HMRC is posted there. Many non-resident founders therefore appoint a Corporate Services Provider to receive mail, maintain statutory registers and manage filings. We support overseas clients through these tasks as part of our company setup in the UK, including registered office provision and ongoing secretarial support.
Conclusion
The first 90 days after Companies House approval are where good habits form. Together, these early tasks build a compliance foundation that protects both the company and its directors:
- Secure the certificate, authentication code and UTR
- Register with HMRC on time
- Diarise the confirmation statement, accounts and Corporation Tax deadlines
Setting up business in the UK is quick, but staying compliant is a continuous obligation. Penalties have risen sharply for 2026, and the tax payment and filing deadlines run on separate clocks that regularly catch new founders out.
As a Corporate Services Provider, 3E Accounting United Kingdom supports businesses through incorporation and registered office provision. We also handle Corporation Tax and VAT registration, plus ongoing secretarial compliance. Backed by our international network spanning more than 110 countries, we combine professional expertise with technology-enabled processes. This lets clients grow in the UK and beyond with confidence.
Navigate the First 90 Days With Confidence
Let 3E Accounting United Kingdom handle your post-incorporation registrations, statutory filings and ongoing compliance so nothing slips through the cracks.
Frequently Asked Questions
No. The obligation arises within three months of starting to trade, which usually means the first invoice, deposit or contract. Dormant companies generally do not need to register until activity begins.
Registration becomes mandatory once taxable turnover exceeds £90,000 in any rolling 12-month period, or is expected to exceed it within the next 30 days alone. Voluntary registration is also possible below the threshold.
It falls due 12 months after incorporation, with 14 days to file. From 1 February 2026, the Companies House online filing fee is £50, or £110 on paper.
From 1 April 2026, the fixed penalty is £200 one day late and £400 if more than three months late, with 10% surcharges at six and twelve months on HMRC's estimated tax. Three consecutive late filings raise the fixed penalty further.
Yes. Non-resident directors must maintain a UK registered office address and meet all Companies House and HMRC deadlines, exactly as resident directors do. Many appoint a Corporate Services Provider to manage filings and mail handling.
Abigail Yu
Author
Abigail Yu oversees executive leadership at 3E Accounting Group, leading operations, IT solutions, public relations, and digital marketing to drive business success. She holds an honors degree in Communication and New Media from the National University of Singapore and is highly skilled in crisis management, financial communication, and corporate communications.
