Running a limited company means you’ve got tax to think about, and honestly, it’s a lot easier if you know your Corporation Tax bill ahead of time. Our Corporation Tax Calculator gives you a quick estimate of how much corporation tax your company owes based on the profit. Just enter your profit and you’ll see an instant calculation.
We’ve designed the calculator using the 2025/26 UK Corporation Tax rates from HMRC. It reflects how Corporation Tax works in practice and all the things that really impact your bill. The aim? You get a realistic sense of what you’ll owe, so there are no surprises when it’s time to pay.
If you’re a UK limited company director or a contractor running your own business, this calculator is for you. Whether you’re managing cash flow, making sure you’ve saved enough for tax, or double-checking before speaking with your accountant, this calculator gives you a reliable starting point.
We know trust is everything when it comes to tax. That’s why we have built this calculator considering HMRC guidance and with input from experienced accounting professionals who work with limited companies every day. While it’s just an estimate and not official advice, it’s accurate, open, and simple calculator to plan tax with confidence.
How to Use Our Corporation Tax Calculator
Our Corporation Tax Calculator follows the same basic steps a UK limited company uses to work out its tax position. We keep things simple and transparent, so you can see exactly how we arrive at the final figure and what factors affect your tax.
Step 1. Select Your Gross Profit
Drag the slider to match your total gross profit for the financial year 2025/26. This is the profit your company has made before any expenses are deducted. It includes all allowable limited company expenses, cost of depreciation value of your assets. It’s important to get this number right, since Corporation Tax is based on profits, not total sales.
Step 2. Identify your tax band
Next, the calculator compares your profit to the UK Corporation Tax bands. If your company’s profits are lower, the small profits rate is applied. If your profits are higher, the main rate applies. If your profits fall in between, the calculator takes marginal relief into account.
Step 3. Apply the correct Corporation Tax rate
Based on your profit, we use the tax rate set by HMRC for the 2025/26 year.
Step 4. Calculate marginal relief if applicable
If your company qualifies for marginal relief, the calculator works out the relief for you, reducing your tax bill when your profits are between the lower and upper thresholds.
What the Calculator Shows You
After the calculation, you’ll see a clear summary:
Net profit
This is the profit used for tax purposes, after allowable expenses.
Small profits tax
If you qualify for the lower band, this shows the tax calculated at the small profits rate.
Main rate tax
For higher profits, this displays the tax at the main rate.
Marginal relief rebate
If you’re eligible, this shows how much your tax is reduced due to marginal relief.
Amount due
This is your estimated Corporation Tax bill payable to HMRC.
Profit after tax
This is what remains in your company after paying Corporation Tax.
Effective tax rate
The actual percentage of tax paid on your profits.
The calculator is designed to help you plan and make decisions, using up-to-date UK tax regulations. For precise figures and professional tax advice, it’s always best to consult a qualified limited company accountant.
UK Corporation Tax Rates 2025/26
Corporation tax rates in the UK depend on your company’s profits for each accounting period. The more profit your business earns, the more tax you’ll owe; it’s as simple as that. Knowing which rate applies helps you plan, budget effectively, and avoid any unexpected bills.
Here’s how it works for the 2025–2026 tax year.
Small profits rate
This applies to companies with lower taxable profits. If your profits are at or below the lower limit, you pay a reduced rate which means less tax goes out, and more money stays in your business. It’s designed to give smaller companies some support by keeping their tax bill lower.
Main rate
If your profits go above the upper limit, you pay the main rate on everything you earn. Higher profits mean a higher tax bill.
Marginal relief
If your company’s profits fall between the lower and upper limits? You don’t immediately jump from the small profits rate to the main rate. Instead, you benefit from what’s called marginal relief. This helps the tax rate rise gradually as your profits increase, avoiding any sharp jumps.
Accounting period considerations
Corporation Tax is worked out for each accounting period, usually 12 months. If your accounting period is shorter (covers parts of two tax years or maybe you’re just starting, or you’ve changed your year end), the profit limits and rates are adjusted accordingly. This keeps things fair, but it means you’ll need to pay attention if your business doesn’t follow the standard calendar year.
| Company Profit | Rate Type | Corporation Rate % |
| More than £250,000 | Main rate | 25% |
| Less than £50,000 | Small profits rate | 19% |
| £50,000 - £250,000 | Main rate with marginal relief | 25% and reduced by marginal relief |
Corporation Tax Deadlines You Need to Know
Corporation Tax payment deadline
- Corporation Tax is usually due 9 months and 1 day after the end of your accounting period
- For example, if your year end is 31 March, payment is normally due by 1 January
- Payment is made directly to HMRC and is separate from filing your tax return
Filing deadline for the CT600
- You must file Company Tax Return within 12 months of the end of the accounting period
- This applies even if your company is dormant, makes a loss or has no Corporation Tax to pay
Is this Limited Company Tax Calculator Accurate?
We created this Corporation Tax Calculator using up-to-date HMRC guidance and UK regulations. It calculates your figures the same way most limited companies do, taking into account profit thresholds and any applicable reliefs. The aim? To give you a clear estimate you can rely on for planning and decision-making without any guesswork.
Remember, this is just an estimate and not your official tax bill. It doesn’t replace a full review of your accounts or advice from a professional. Factors like associated companies, adjustments, or business changes could all impact your actual amount.
We keep our calculator aligned with latest HMRC rates and rules but real tax calculation may vary. Always double-check your final numbers before submitting to HMRC. An accountant for limited company can help ensure everything is accurate and your company’s tax is correct.
Who Should Use This Corporation Tax Calculator?
- Limited company directors
Directors can use the calculator to estimate their company’s Corporation Tax bill, plan cash flow, and set aside funds ahead of payment deadlines. - Contractors outside IR35
Contractors trading through their own limited companies can use the tool to get a quick view of their tax position based on company profits. - Small business owners
Small business owners can use the calculator to understand how profits affect Corporation Tax and to support budgeting and financial planning. - Start ups
New companies can use the calculator to get an early idea of potential tax costs and build better financial habits from the start.
Want to reduce your Corporation Tax bill?
If you want to reduce your Corporation Tax in a legitimate and practical way, having a skilled accountant on your side can make a real difference. They’ll look closely at your finances and find reliefs, allowances, and planning options that actually work for your business.
Speak with our limited company accountant for a tax review that’s tailored to your company, not just a sales pitch. You’ll receive honest advice, accurate figures, and the support you genuinely need. Whether you’re looking for a second opinion or ongoing advice, we’ll help clarify your situation and give you greater peace of mind.
FAQs
What is Corporation Tax?
Corporation Tax is a tax that UK limited companies pay on their profits. It applies to trading profits, investment income, and gains made from selling company assets, and is paid directly to HMRC.
Who has to pay Corporation Tax?
All UK limited companies must pay Corporation Tax on their taxable profits. This also applies to foreign companies with a UK branch or office, and some unincorporated associations, clubs, co operatives too.
What is the current Corporation Tax rate?
In the UK the main rate of Corporation Tax is 25% for companies with profits over £250,000. Companies with profits of £50,000 or less pay a small profits rate of 19%, and profits between those figures may attract marginal relief that gradually increases the effective rate.
When do I need to pay Corporation Tax?
You must pay Corporation Tax within 9 months and 1 day after the end of your accounting period. For example, if your year-end is 31 March, the tax is due by 1 January the following year.
When do I need to file my Corporation Tax return?
You must file your Corporation Tax return (CT600) within 12 months after the end of your accounting period. It must be submitted online using iXBRL format.
Can I carry forward losses?
Yes, UK companies can usually carry forward trading losses to offset against future profits. This can reduce Corporation Tax in later years, helping manage cash flow and tax liability.
How accurate is a Corporation Tax Calculator?
Our UK Corporation Tax Calculator is accurate for estimates when you enter correct profit figures and it uses current HMRC rules. It shows a realistic tax position for most UK companies, but final tax can vary due to reliefs, adjustments, or company specific factors.
What tax year does this calculator use?
This calculator uses the current UK Corporation Tax rules for the 2025/26 tax year. Rates and thresholds are updated in line with HMRC guidance, so the results reflect the latest published figures.
Do I need an accountant to handle Corporation Tax?
It’s not a legal requirement, but most businesses use an accountant to check figures, apply reliefs correctly, and confirm final Corporation Tax position before submission to HMRC.
Is corporation tax calculated after dividends?
No, Corporation Tax is calculated before dividends are paid. A company pays Corporation Tax on its taxable profits first, and dividends are then paid from the remaining profit after tax.
How much can a company earn before paying corporation tax?
A UK company does not have a tax free allowance for Corporation Tax. Corporation Tax applies to all taxable profits, with profits up to 50000 charged at the small profits rate and higher profits taxed at higher rates.
Is corporation tax based on turnover or profit?
Corporation Tax in the UK is based on profit, not turnover. The tax is calculated after allowable business expenses are deducted from income, which means only taxable profit is charged to Corporation Tax.
How much is corporation tax for a limited company in 2026?
For the 2026 financial year, most UK limited companies will pay Corporation Tax at the same rates set for earlier years. That means profits over £250,000 are taxed at the main rate of 25 percent, while profits up to £50,000 are taxed at the small profits rate of 19 percent. Companies with profits between those limits pay a rate that rises gradually through marginal relief.
Do all limited companies have to pay corporation tax?
Most UK limited companies must pay Corporation Tax on taxable profits. If a company makes a loss or is dormant, it may not pay tax, but it still needs to report its position to HMRC.
How can I reduce my Corporation Tax bill legally?
You can reduce your Corporation Tax bill legally by claiming all allowable business expenses, making pension contributions, and using available reliefs such as capital allowances. Planning the timing of income and costs can also help lower taxable profits.
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