Inheritance tax after a sale calculator

Quite possibly. Shares in an unquoted trading company often qualify for Business Relief, but cash from a sale usually doesn't. So, unless you plan for it, the proceeds form part of your estate and can be taxed at 40% above your available nil-rate bands. The calculator shows how much the sale could add.

It works out the inheritance tax on your estate twice. Before the sale, your shares get Business Relief at 100% on the first £2.5m and 50% above that. After the sale, the shares are treated as cash with no relief. The headline figure is the difference, if you died after the sale with the proceeds still held as cash.

It's a simplified estimate for one person. It assumes no lifetime gifts, no spouse or charity exemption, no transferred allowances, and that the sale proceeds are held as cash. It also assumes your shares would qualify for Business Relief before the sale, and it ignores the capital gains tax on the sale, which would reduce the cash.

From 6 April 2026, 100% Business Relief applies only to the first £2.5m of combined qualifying business and agricultural property per person, with 50% relief above that. So even before a sale, a valuable shareholding can bear some inheritance tax. The calculator uses these rules for the before-sale figure.

The residence nil-rate band of £175,000 is only available when a home passes to direct descendants, such as children or grandchildren. It's tapered away for estates over £2m, and the calculator applies the taper to the value of your estate before reliefs. On a large sale, the residence nil-rate band may be reduced or lost.

Business Relief is usually lost from the date of a binding contract for sale, not just at completion. Once the shares are sold for cash, the proceeds usually don't qualify. That's why it's worth looking at inheritance tax before a sale is agreed, rather than after the money arrives.

No. It treats the full value of your shares as cash after the sale and ignores the capital gains tax you'd pay, which would reduce the cash in your estate. To estimate that tax, use the capital gains tax on selling shares calculator, then reduce the value you enter here if you want a closer figure.

It's still a useful guide, but it's an estimate for one person and ignores the spouse exemption and any allowances transferred from a spouse or civil partner. Couples often have more options, and the real position depends on both estates and both wills. Treat the result as an indication of the scale of the issue.

No. The calculator runs in your browser, and the figures you enter aren't stored or sent anywhere. If you accept analytics cookies, we record only that the tool was used, not what you entered. You don't need to give your name or email address to use it.

Look at inheritance tax before you agree the sale, as the options narrow once shares become cash. Planning often involves your wider family and other advisers, such as your lawyer for wills and trusts. To talk through the tax side, book a call or email taxadvisory@aswatax.co.uk, and we'll reply within one working day.