Accounting for Startups
An accounting guide for UK startups, from formation and SEIS/EIS compliance to R&D tax credits, fundraising and financial reporting.
Starting a business in the UK is exciting. Doing the accounting for it is less exciting, but getting it wrong early on creates problems that compound as you grow. Investors, HMRC and Companies House all expect your financial records to be accurate and up to date from day one.
The good news is that startup accounting does not need to be complicated in the early stages. Start with the basics, build good habits and scale your finance function as the business grows.
Setting up your company
Most UK startups incorporate as a private limited company (Ltd). This provides limited liability, a clear structure for investment and credibility with customers and partners.
Key setup steps
- Register at Companies House (£12 online, takes 24-48 hours)
- Register for Corporation Tax with HMRC (within 3 months of starting to trade)
- Open a business bank account – you cannot use a personal account for a limited company
- Set up accounting software from the start
- Register for VAT if turnover will exceed £90,000, or voluntarily if it benefits you
- Register as an employer with HMRC if you will pay anyone (including yourself a salary)
Share structure
Think carefully about your share structure at incorporation. A simple setup for co-founders:
| Element | Typical approach |
|---|---|
| Share classes | Ordinary shares for founders; separate class for investor shares later |
| Nominal value | £0.001 per share (allows more shares and easier splitting) |
| Vesting | Founders should consider reverse vesting (shares subject to buyback if a founder leaves early) |
| Articles of association | Use bespoke articles if you plan to raise investment; model articles work for simpler setups |
Get legal advice on share structure before you issue shares. Restructuring later is expensive and can trigger tax charges.
SEIS and EIS
The Seed Enterprise Investment Scheme (SEIS) and Enterprise Investment Scheme (EIS) are powerful tools for UK startups raising investment. They offer tax reliefs to investors who buy shares in qualifying companies.
| Feature | SEIS | EIS |
|---|---|---|
| Income Tax relief for investor | 50% of amount invested | 30% of amount invested |
| Maximum investment per company | £250,000 | £12 million (lifetime) |
| CGT exemption | Gains on SEIS shares are exempt | Gains deferred or exempt if held 3+ years |
| Loss relief | Investor can offset losses against income | Same |
| Company age limit | Under 3 years old | Under 7 years (or 10 for knowledge-intensive companies) |
| Company asset limit | Under £350,000 gross assets | Under £15 million gross assets before investment |
| Employee limit | Under 25 full-time equivalent | Under 250 (500 for knowledge-intensive) |
Advance assurance
Before raising investment under SEIS/EIS, apply for advance assurance from HMRC. This confirms that your company qualifies, giving investors confidence before they commit. The process takes 4-6 weeks.
What can disqualify you
- Trading in excluded activities (property development, financial services, legal services, certain others)
- Receiving investment from a connected party (someone who already holds 30%+ of the company)
- Not spending the money on qualifying business activity within the required timeframe
- Having too many assets or employees at the time of investment
Keep detailed records of how SEIS/EIS funds are spent. HMRC can review this retrospectively and claw back investors’ tax relief if the company was not qualifying.
R&D tax credits
If your startup is developing new products, processes or services that involve a technological advance, you may qualify for R&D tax credits. This is one of the most valuable reliefs available to UK startups.
How it works for SMEs
Under the merged R&D scheme (from April 2024), qualifying companies receive an above-the-line tax credit. For loss-making R&D-intensive startups (where qualifying R&D expenditure is 30%+ of total expenditure), the effective credit rate can be particularly generous, with a payable credit available in cash.
Qualifying costs include:
- Staff costs – salaries, employer NIC and pension contributions for employees directly engaged in R&D
- Subcontractor costs – up to 65% of payments to subcontractors for R&D work
- Consumables – materials, utilities and software used in R&D
- Cloud computing – costs directly attributable to R&D activities
Record-keeping for R&D claims
You must be able to demonstrate:
- What technological uncertainty you were trying to resolve
- What advance in science or technology you sought to achieve
- How the work went beyond routine engineering
- What costs were directly attributable to the R&D activity
Keep contemporaneous records – project plans, technical documents, timesheets, meeting notes. Retrospective claims based on vague descriptions are increasingly challenged by HMRC.
Fundraising accounting
When you raise investment, the accounting entries depend on the type of funding:
Equity investment (selling shares)
When an investor pays £100,000 for shares with a nominal value of £100:
| Account | Debit | Credit |
|---|---|---|
| Bank | £100,000 | |
| Share capital | £100 | |
| Share premium | £99,900 |
The share premium account represents the excess paid over the nominal value. It has restrictions on how it can be used (it cannot be distributed as dividends).
Convertible loan notes
A common instrument for early-stage fundraising. Initially recorded as a liability; converts to equity at a future funding round (usually at a discount to the new round price).
Grants
Grants are recognised as income when the conditions attached to them are met. If a grant has conditions you have not yet fulfilled, it should be shown as deferred income on your balance sheet.
Payroll
Once you start paying anyone – including yourself – you need to run a PAYE payroll .
Founder salary
Most startup founders pay themselves a modest salary (often at or below the personal allowance of £12,570) and take additional income as dividends once the company is profitable. This minimises NIC.
If the company is loss-making (common in early stages), paying yourself a salary increases the company’s losses, which can be carried forward against future profits for Corporation Tax purposes.
EMI share options
The Enterprise Management Incentive (EMI) scheme allows startups to grant share options to employees with significant tax advantages:
- No Income Tax or NIC on the option grant (if exercise price equals market value)
- Capital Gains Tax (not Income Tax) on the eventual sale of shares
- CGT at 10% under Business Asset Disposal Relief (if conditions are met), compared to up to 45% Income Tax on equivalent salary
EMI options are available to companies with gross assets under £30 million and fewer than 250 employees. You can grant options worth up to £250,000 per employee.
Financial reporting
As a startup limited company, your minimum filing requirements are:
| Filing | Where | Deadline |
|---|---|---|
| Annual accounts | Companies House | 9 months after year end |
| Corporation Tax return (CT600) | HMRC | 12 months after year end |
| Confirmation statement | Companies House | Annually |
| VAT returns | HMRC | Quarterly (if registered) |
| PAYE RTI | HMRC | On or before each pay date |
If you qualify as a small company (most startups do), you can file abbreviated accounts at Companies House, keeping detailed financial information private.
Management accounts
Even if not legally required, produce monthly management accounts from the start:
- Profit and loss – are you burning cash faster than expected?
- Balance sheet – how much cash do you have left?
- Cash flow forecast – when will you run out of money?
- Runway – months of operating expenses covered by current cash
Investors will expect to see these, and they are essential for your own decision-making.
Common startup accounting mistakes
- Mixing personal and company money – use a business bank account from day one
- Not tracking expenses from pre-incorporation – costs incurred up to 7 years before incorporation can be claimed if they would have been deductible had the company existed at the time
- Sloppy share documentation – share issues without proper board minutes and stock transfer forms create problems during due diligence
- Not claiming R&D tax credits – many startups do not realise they qualify
- Ignoring SEIS/EIS compliance – losing advance assurance status retroactively harms your investors
- Not producing management accounts – flying blind on cash flow is the most common reason startups fail
- Over-complicated structures – keep things simple until complexity is genuinely needed
Getting your accounting right from the start
- Choose accounting software and set it up properly – chart of accounts, bank feeds, VAT settings
- Record everything from day one – even before you have revenue
- Keep personal and business finances completely separate
- File on time, every time – late filing destroys your credit score and triggers penalties
- Get an accountant who understands startups – SEIS/EIS, R&D claims and fundraising are specialist areas
- Produce monthly management accounts – even if only you read them