Confidential Corporation Tax Planner — No Business Data Stored
Plan your corporation tax for US and UK businesses. Calculate taxable profit, tax liability, effective rate, and marginal rate. All calculations are confidential and processed entirely in your browser — your financial data is never transmitted or stored.
How Corporation Tax Works
Corporation tax (corporate income tax) is levied on a company's profits after allowable expenses. The US uses a flat 21% federal rate, while the UK has a tiered system with a small profits rate (19%) and main rate (25%), with marginal relief for profits between £50,000 and £250,000.
US Corporate Tax Rate
- Federal Rate: Flat 21% on all taxable corporate profits
- State Rates: Vary from 0% (e.g., Wyoming, Nevada) to ~11.5% (New Jersey)
- Effective Rate: Federal + state, less deduction of state taxes on federal return
UK Corporation Tax Rates (2024/25)
- Small Profits Rate: 19% on profits up to £50,000
- Main Rate: 25% on profits above £250,000
- Marginal Relief Band: £50,000–£250,000 (effective rate 26.5% on profits in this band)
- Marginal Relief Formula: Main rate tax minus (£250,000 − profits) × (profits / profits) × 3/200
Allowable Expenses
Allowable expenses reduce your taxable profit. Common deductions include employee salaries, rent, utilities, professional services, marketing costs, depreciation (capital allowances), and research & development credits. Proper expense tracking can significantly reduce your tax liability.
Privacy Guarantee
Your business profits, expenses, and tax calculations are processed entirely in your browser. No financial data is sent to any server, stored in any database, or shared with any third party. Your business intelligence remains confidential.
Tips for Effective Tracking
Consistency is more important than perfection — update your tracker regularly even if the data is not perfect. Set a daily reminder to log your entries while they are fresh. Review your progress weekly to spot patterns and make adjustments. Your data is saved automatically in your browser, so you do not need to worry about losing it between sessions. Export or screenshot your data periodically as a backup.
Frequently Asked Questions
Is my business financial data kept confidential?
Yes — completely. All tax calculations run in your browser. No profit figures, expenses, or results are sent to any server, stored anywhere, or tracked in any way. Your business intelligence remains private.
What is the US corporate tax rate?
The US federal corporate tax rate is a flat 21% on all taxable profits, established by the Tax Cuts and Jobs Act of 2017. State corporate taxes range from 0% to approximately 11.5%, depending on the state.
How does UK corporation tax marginal relief work?
For profits between £50,000 and £250,000, the tax is calculated at the main rate (25%) minus marginal relief. The formula is: (£250,000 - profits) x 3/200. This creates an effective marginal rate of 26.5% on profits in this band, smoothly transitioning from the 19% small profits rate to the 25% main rate.
What counts as an allowable expense?
Allowable expenses include costs incurred wholly and exclusively for business purposes: staff salaries, office rent, utilities, marketing, professional fees, travel, equipment depreciation (capital allowances), and R&D tax credits. Personal expenses and entertainment costs are generally not deductible.
Is Confidential Corporation Tax Planner — No Business Data Stored free to use?
Yes, Confidential Corporation Tax Planner — No Business Data Stored is completely free with no sign-up, no login, and no hidden fees. The tool runs entirely in your browser — your data never leaves your device.