The high-impact levers
UK corporation tax runs at 25% main rate (profits over £250,000), tapered to 19% for profits under £50,000, with marginal relief in between. Every £1 you reduce chargeable profit by saves you 19-25p. For a one-person limited-company freelancer, the levers that materially reduce corporation tax are pension contributions, capital allowances on equipment, and genuine business expenses — not clever schemes.
The high-impact levers
Employer pension contributions — the company pays into your pension pre-tax. Reduces chargeable profit £-for-£, saves you 19-25% CT, and doesn't count as personal income. Annual allowance is £60,000 in 2025/26 with carry-forward for up to three years.
Annual Investment Allowance (AIA) — 100% first-year deduction on qualifying equipment up to £1,000,000/year. Bought a £3,000 laptop + £1,500 camera in the tax year? Deduct £4,500 from profit — saves £900-1,125 in CT.
Genuine business expenses — travel, subsistence when away overnight, business phone and broadband proportion, subscriptions and software, professional fees, accountant fees, business insurance.
Timing decisions that compound
Bringing equipment purchases forward from Q1 next year to Q4 this year moves the AIA deduction into the earlier tax year — accelerates the tax relief by 12 months. Similarly, pension contributions timed near the year-end shift the CT bill into the following year while claiming the current-year relief.
Profit retention inside the company is also a timing choice. You'll pay 25% CT now, but you defer personal tax on the extraction until you actually take dividends — potentially spreading them across multiple tax years to stay within basic-rate bands.
Levers to leave alone
Sham arrangements. Overpaying yourself and your spouse. Charging the company for a home office you don't have. Claiming personal expenses. HMRC's data-matching capabilities catch these; the penalty regime is severe.
Closer to the line but still legitimate: research and development tax credits (only if you're doing genuinely novel technical work — most freelance dev work isn't R&D), employing genuine family members (only if they actually do the work), and using patent-box relief (very niche).
Worked example
Kim's Ltd has £75,000 chargeable profit for the year. CT at the small-profits rate (19%) = £14,250. She makes: (1) A £15,000 employer pension contribution reducing profit to £60,000. (2) Bought a £4,000 laptop + £2,000 monitor + £1,500 office chair = £7,500 AIA. Profit down to £52,500. CT now £9,975 — saving of £4,275. She's added £15,000 to her pension and £7,500 of business equipment for a net CT cost £4,275 less than starting position. The pension money is also outside her personal income entirely, so no dividend tax later on that £15,000.
Reference table
| Lever | Annual limit | CT saving on £10,000 spend |
|---|---|---|
| Employer pension contribution | £60,000 (+ carry-forward) | £1,900-£2,500 |
| Annual Investment Allowance | £1,000,000/year | £1,900-£2,500 |
| Charitable donation from company | No limit if trading purpose | £1,900-£2,500 |
| R&D tax credit (if qualifying) | Complex | Up to £2,700 for SME |
| Genuine business insurance | No specific limit | £1,900-£2,500 |
Legitimate CT reduction checklist
- Set up an employer pension scheme (SIPP or workplace scheme) if not already in place
- Review three-year carry-forward of unused pension annual allowance
- Bring necessary equipment purchases into the current tax year where cash-flow permits
- Confirm every claimed expense is wholly and exclusively for business
- Check whether any of this year's development work meets HMRC's R&D definition
- Consider spousal share-splitting if the spouse is genuinely involved
- Retain profit that will be extracted later at a lower personal tax rate
- Get an accountant to review before year-end — the fee usually pays back
Yes. Employer contributions are treated as a business expense and reduce chargeable profit £-for-£, saving 19-25% CT on the contribution amount. No employer NI applies. This is often the single biggest legitimate CT-reduction lever.
Partly. You need to apportion — typically 30-60% business use for a home-working freelancer. Claim the business proportion. HMRC will accept reasonable apportionment; they won't accept 100% on a shared line.
Depreciation is an accounting concept and not tax-deductible in the UK. AIA lets you deduct 100% of qualifying capital spend in year one for tax purposes. So the accounting depreciation is added back, and AIA is deducted instead.
Only when extracted. The company pays 19-25% CT on the profit. If you leave it in the company, no further tax that year. When you eventually take it as dividends, you pay dividend tax on top. If you invest the retained profit through the company, gains are inside the company.
Only if you're doing genuinely novel technical work that resolves technical uncertainty. Most freelance software work is not R&D under HMRC's definition. The claim process is complex and HMRC scrutinises heavily — worth a specialist adviser if applicable.
Sources & official references
Related on FreelanceToolkit UK
This guide is general information based on UK rules for the 2025/26 tax year. It is not personal tax or legal advice. For decisions affecting your tax position or legal exposure, consult a qualified accountant or solicitor.