Marginal relief produces an effective rate above the main rate between the two profit limits. How the spike works and what it implies for the timing of profit.
- Marginal relief band (£50,000–£250,000 profit)
- Split CT600 filing and payment dates
- Why does the £50,000–£250,000 profit band matter for corporation tax?
Operating in the UK combines a corporation tax structure with a punitive marginal band between £50,000 and £250,000 profit with a post-Brexit immigration regime that now checks salary compliance pay period by pay period rather than annually.
Immigration, not tax, is the structural risk companies underestimate in the UK: a sponsor licence takes time to obtain and is now checked at the level of each individual payslip, not the year as a whole. Companies planning to hire non-UK staff — EU nationals included — should secure sponsor status well ahead of the intended start date, not treat it as a formality alongside the job offer.
What a company pays in United Kingdom. Every figure below is published on the United Kingdom country page.
| United Kingdom | |
|---|---|
| VAT standard rate | 20% |
| VAT reduced rates | 5% (domestic energy, children's car seats, certain medical aids) and 0% zero rate (most food, books, children's clothing, public transport) |
| Accounting standard | UK GAAP (FRS 102), or IFRS for larger and listed entities |
| Annual accounts filing | Corporation Tax (CT600) payment due within 9 months and 1 day of the accounting period end; the CT600 return itself due within 12 months of the period end — two separate deadlines |
| Statutory audit | Statutory audit exemption for small companies meeting 2 of 3 thresholds in both the current and preceding year: turnover < £15M, gross assets < £7.5M, < 50 employees (thresholds effective from 6 April 2025) |
What makes it complex in United Kingdom
- Marginal relief band (£50,000–£250,000 profit) — — the effective corporation tax rate on income within this band reaches approximately 26.5%, higher than either the 19% or 25% headline rates, making profit-timing genuinely consequential near the boundary.
- Split CT600 filing and payment dates — — Corporation Tax must be paid within 9 months and 1 day of the accounting period end, but the CT600 return itself is not due until 12 months after: two deadlines three months apart, tracked independently.
Why does the £50,000–£250,000 profit band matter for corporation tax?
Profits in this band are taxed via marginal relief, which produces an effective rate of approximately 26.5% on each additional pound of profit within it — higher than both the 19% small profits rate and the 25% main rate. Companies near either boundary should model the tax impact of crossing it.
Marginal relief band (£50,000–£250,000 profit) is one of the points HTLC Network handles for clients operating in United Kingdom, within a single engagement that covers every other country they operate in — executed locally, governed centrally.
In United Kingdom the scope is: Statutory accounts under UK GAAP (FRS 102) or IFRS, VAT returns at the 20% standard rate, and CT600 corporation tax filings tracking the marginal relief band.
See Accounting & Tax Compliance in United Kingdom for the full scope, or the United Kingdom country page for the statutory framework across every service.
Figures as published on the HTLC Network country pages, reviewed September 2026 and collected from public sources. They are not a substitute for advice on a specific case and should be verified before being relied on.