Read this first. It takes twenty seconds and it matters.

What this is. An illustration built entirely from the numbers you enter. Nothing else goes into it. Change a number and the whole page changes with it, because there is nothing behind it except arithmetic on your own figures.

What this is not. It is not tax advice, accounting advice or financial advice, and it is not a promise about what will happen at your firm. It cannot see your books, your VAT position, your capital allowances or anything else your accountant knows about you. Please talk to your accountant before you act on anything here.

Where the tax numbers come from. The tax arithmetic uses published UK rates for the 2026/27 tax year, read on 14 September 2026. The sources are linked at the bottom of the tool, and we review them by 6 April 2027.

About the boxes we fill in for you. A few start with a number so the page has something to show you. Every one of those is labelled as our assumption and every one of them is yours to change. The two estimates that drive the whole result start at nothing, because they are yours to set and not ours to guess.

What leaves this page. Nothing you type leaves your browser, unless you ask us to email you this page. Then your address and the link to this page, with your figures in it, go to our email sender. If you tick the news box we keep your address on the news list, and nothing else. We never store your figures. There is no account and no sign in. The sums run on your own phone or computer, and the page saves nothing of its own.