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All calculators & tools

12 free tools and counting — each one shows its working, states its assumptions, and links the official source.

UK Contractor & Tax Tools

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CIS Tax Refund Calculator

If you work under the Construction Industry Scheme, your contractor takes tax off before you're paid — and most subcontractors have paid too much. This works out a rough estimate of what you might be owed.

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Company Car BIK Calculator

A company car is a taxable perk. How much you pay depends on the car's value, its emissions and your own tax band — electric cars are taxed far more lightly than petrol or diesel.

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Corporation Tax Calculator

Company profit isn't taxed at a single flat rate. This works out your corporation tax including marginal relief, and shows the effective rate you'll actually pay.

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IR35 Take-Home Calculator

An IR35 determination can be worth thousands a year. This compares your estimated take-home pay inside versus outside IR35, so you can see exactly what the decision costs you.

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Late Filing & Late Payment Penalty Calculator

Missed the Self Assessment deadline? Penalties stack up the longer you leave it. This estimates what filing and paying late is likely to cost you.

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Payment on Account Calculator

That bigger-than-expected January bill is usually payments on account. This works out what you'll owe in January and July, and whether they apply to you in the first place.

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Side Hustle Tax Calculator UK

Selling online, freelancing at weekends or doing a bit of tutoring? Here's a rough idea of how much of your side income to keep back for tax.

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Umbrella vs Limited Company Calculator

Two contractors on the same day rate can end up with very different take-home pay depending on how they're set up. This compares the two routes side by side.

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Dividend Tax Calculator

Dividend tax rates went up in April 2026, so a strategy that worked last year might cost you more now. Enter your figures to see what you'll actually pay this tax year.

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Salary vs Dividend Calculator

For a single-director company, how should you take money out — all salary, or a small salary plus dividends? Enter the profit you want to extract and see which leaves more in your pocket this tax year.

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