What are the Corporation Tax rates in the UK?

The small profits rate is 19% for taxable profits up to £50,000. The main corporate tax rate is 25% for profits exceeding £250,000.

How does Marginal Relief work for corporate profits between £50,000 and £250,000?

Marginal Relief provides a gradual sliding-scale taper between 19% and 25%, computed using the statutory Marginal Relief fraction (3/400ths).

How do associated companies affect the £50,000 and £250,000 profit thresholds?

The lower and upper profit limits are divided equally by the total number of associated companies under common corporate control.

What is the deadline for paying UK Corporation Tax to HMRC?

Corporation Tax must be paid electronically within 9 months and 1 day after the end of the company's accounting period for non-large companies.

Can full expensing capital allowances reduce taxable corporate profits?

Yes, qualifying plant and machinery investments qualify for 100% first-year full expensing or the Annual Investment Allowance (AIA) up to £1,000,000.

HMRC Corporate Taxation

UK Corporation Tax & Marginal Relief Calculator

Calculate your company's UK Corporation Tax liability under HM Revenue & Customs (HMRC). Model the 19.0% Small Profits Rate (profits up to £50,000), the 25.0% Main Rate (profits over £250,000), and the 3/200 Marginal Relief fraction on profits between £50k and £250k, adjusted for associated companies.

Company Profit & Structure

Annual Taxable Trading Profits (£) Tax-adjusted trading and non-trading profits (after capital allowances and loss relief).

Number of Associated Companies Under 51% common control. Each associated company reduces the £50k and £250k thresholds proportionately.

Accounting Period Duration (Months) Standard accounting year is 12 months. Shorter periods prorate the threshold limits.

Director / Shareholder Dividend Distribution (£) Amount paid out as dividends from post-tax retained profits.

HMRC Tax Assessment Summary

Total Corporation Tax Due £0 Effective Rate: 0.00%

Retained Company Profit £0 Post-tax retained cash

Marginal Relief Deduction -£0 3/200 fraction applied

Tax Rate Bracket Marginal Relief £50,000 - £250,000

Effective Marginal Tax Rate 26.50% On profits between limits

Post-Tax Retained Reserves £0 After dividend payout

Detailed Statutory Computation

Calculation Step	HMRC Statutory Formula	Applied Factor	Amount (£)

Understanding the UK Corporation Tax System

1. How does the UK Corporation Tax tier system work?

Since 1 April 2023, UK Corporation Tax operates under a two-tier regime:

Small Profits Rate (19.0%): Applies to companies with taxable profits up to £50,000.
Main Rate (25.0%): Applies to companies with taxable profits exceeding £250,000.
Marginal Relief: Provides a gradual tapering transition for profits between £50,000 and £250,000 to ensure there is no cliff-edge increase.

2. What is the Marginal Relief formula and why is the marginal rate 26.5%?

HMRC calculates Marginal Relief using the statutory fraction 3/200 (0.015):

Marginal Relief = (Upper Limit - Profit) × 3/200

The total tax is calculated as: (Profit × 25%) - Marginal Relief. Because every additional pound earned between £50,000 and £250,000 is taxed at 25% while simultaneously reducing your marginal relief by 1.5p, the marginal tax rate on profits within the relief band is exactly 26.5%.

3. How do Associated Companies affect the limits?

If your company has associated companies under common shareholder control, both the £50,000 lower limit and the £250,000 upper limit are divided by (1 + number of associated companies). For example, if you control 2 companies, the lower threshold becomes £25,000 and the upper threshold becomes £125,000 for each company.

📊 United Kingdom Statutory Breakdown Matrix (HMRC & UK Regulations)

Statutory Component / Legal Deduction Item	Calculated Amount (GBP / £)
Primary Net / Statutory Payable Amount	£0.00

Engr. Muhammad Shahzad

Principal Financial Systems Architect & United Kingdom Statutory Specialist

Lead software and systems architect specializing in high-performance browser computing, algorithmic validation, financial models, and zero-telemetry client-side privacy architecture.

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