Sold to a Family Member at a Loss? Why HMRC Freezes That Capital Loss 2026/27

A loss made on a sale to a relative is real, but it goes into quarantine. Here is how the freeze works and how a frozen loss can eventually thaw.

Zazentax Connected Persons Series, Part 2 of 3 · Updated July 2026 · Reading time: about 5 minutes

Capital losses are usually a small consolation prize from the tax system. When an asset is sold for less than it cost, the loss can normally be set against gains made in the same year, and anything left over rolls forward against gains in future years. That flexibility is what makes losses valuable. Sell the losing asset to your sister, however, and the consolation prize is locked in a box.

The rule exists because of a temptation. Without it, anyone holding an asset that had fallen in value could sell it cheaply to a relative, harvest the loss to wipe out tax on other gains, and keep the asset comfortably inside the family. The law removes that temptation with a targeted restriction, and understanding it prevents both an unpleasant surprise and, used carefully, a wasted relief.

The Quarantine Rule

Where a disposal to a connected person produces a capital loss, that loss may only be used against gains arising on later disposals to the same person. It cannot touch your other gains in the same year, it cannot roll forward against general future gains, and it cannot be transferred to anyone else. Accountants call this a clogged loss, and the description is apt: the loss still exists, but it is stuck.

Connected persons for this purpose are the family and business circle covered in Part 1 of this series: your spouse or civil partner, parents, grandparents, children, grandchildren and siblings, the equivalent relatives of your spouse, the spouses of your relatives, your business partners and their close family, and any company you control. Notably, a loss on a transfer to your own spouse cannot even arise in the first place, because spousal transfers happen at no gain and no loss by design.

Key point: The loss itself is calculated using market value, not the price actually paid. Selling an asset to a relative for far less than it is worth does not manufacture a bigger loss; the law measures the fall in value against what the asset would fetch from a stranger.

A Frozen Loss, and How It Thaws

Consider Nadia. Some years ago she paid £30,000 for a painting. Its market value has fallen to £22,000, and she sells it at that fair value to her brother. Her capital loss is £30,000 minus £22,000, which equals £8,000. Because her brother is a connected person, the £8,000 is clogged: it sits in quarantine, usable only against a future gain on another disposal by Nadia to that same brother.

Two years later the thaw arrives. Nadia gives her brother a plot of land, and because gifts to connected persons are deemed to happen at market value, the gift produces a gain of £11,000. Now the frozen loss finally works: £11,000 minus the £8,000 clogged loss leaves £3,000, and since every individual has an annual exempt amount of £3,000 for 2026/27 (the yearly slice of gains that is tax free), her taxable gain that year can fall to nothing. Had she never made another disposal to her brother, the £8,000 would have stayed frozen indefinitely and died with the connection.

Action required: If you are carrying a clogged loss, record it clearly against the name of the person concerned, in your own files and on your tax return. Years may pass before a matching gain appears, and an undocumented clogged loss is the easiest relief in the system to forget.

What This Means for Family Planning

Three practical conclusions follow. First, never sell a loss-making asset to a relative in the hope of using the loss against your other gains; the quarantine defeats the plan by design, and an asset genuinely intended for sale should go to the open market if the loss matters to you. Second, sequence matters within a family: if you know a future gift to the same person is coming, a clogged loss today may be perfectly usable tomorrow, exactly as in Nadia’s case. Third, remember the direction of the rule; it restricts losses, never gains. A gain on a disposal to a relative is taxed in full immediately, while a loss to the same person waits in the freezer. The asymmetry is deliberate, and it is the clearest sign that these rules exist to protect the tax base rather than to punish families.

Key Takeaways

• A capital loss on a disposal to a connected person can only ever be set against gains on later disposals to that same person.
• The loss is measured using market value, so a deliberately low family price cannot inflate it.
• Losses to a spouse or civil partner cannot arise at all, because those transfers pass at no gain and no loss.
• A clogged loss never expires while the connection exists, so document it and watch for a matching gain to the same person.
• Gains to relatives are taxed immediately and in full; only the losses are quarantined.

Carrying a Loss You Are Not Sure You Can Use?

A clogged loss is easy to forget and worth real money when the matching gain arrives. Zazentax can review your position, document what is frozen, and plan the disposal sequence that thaws it.

Talk to Zazentax about your capital losses.