Bed and ISA, CGT Tax Planning Strategy

What Bed and ISA Means

Bed and ISA refers to selling shares or funds held in a general investment account (GIA) and immediately repurchasing the same or equivalent investments inside a Stocks and Shares ISA. The effect is to move holdings from a taxable environment into a tax-free wrapper. Once inside the ISA, all future growth, dividends and capital gains are permanently free from tax, there is no CGT on gains within an ISA, however large they become.

The term derives from the older 'bed and breakfast' strategy, where investors sold and repurchased outside any wrapper to crystallise a gain or loss. Bed and ISA is its successor, instead of repurchasing in the same account, the new holding goes into the ISA. This distinction is crucial for understanding how the tax rules apply.

The CGT Implication of the 'Bed' Part

The sale itself, the 'bed', is a disposal for CGT purposes. If the investment has grown in value, you crystallise a capital gain at the point of sale. That gain uses up your annual exempt amount (£3,000 for 2026/27). If the gain exceeds £3,000, CGT is payable on the excess. If the investment has fallen in value, you crystallise a capital loss, which can offset gains elsewhere.

Ideally, bed and ISA is timed so that gains fall within the annual exempt amount, meaning no CGT arises. An investor with unrealised gains of £3,000 or less can execute the full transfer tax-free each year. Those with larger unrealised gains might split the bed and ISA across two tax years, selling some before 5 April and the rest after 6 April, to use two years' worth of the annual exempt amount.

The 30-Day Rule Does Not Apply to ISA Rebuys

The bed-and-breakfast rule (Section 106A TCGA 1992) matches a sale with any purchase of the same shares within 30 days, neutralising the intended gain or loss crystallisation. This rule is specifically designed to prevent investors from selling and immediately repurchasing in the same account to manipulate their tax position.

Crucially, the 30-day rule does not apply to purchases made inside an ISA. HMRC's position is that an ISA holding is a different legal entity from a direct holding, so the two are not 'the same' investment for matching purposes. You can sell shares in your GIA at 9am and buy the identical shares inside your ISA at 9.05am, and the 30-day rule does not apply. The gain (or loss) on the GIA sale stands in full. This is confirmed in HMRC's Capital Gains manual at CG42562.

When Bed and ISA Makes Sense

Bed and ISA is most valuable for investments with significant unrealised growth that you intend to hold for a long time. The longer you hold, the more future gains accumulate inside the tax-free wrapper, and the greater the CGT saving compared to eventually selling from a GIA. For short-term holdings where you plan to sell within a year or two, the benefit may not justify the transaction costs.

The optimal time to execute is when your unrealised gain is close to (but does not exceed) your remaining annual exempt amount for the year, and when your ISA allowance has not yet been fully used. For a couple, both partners can execute bed and ISA in the same tax year, using their individual AEAs and ISA allowances, up to £40,000 combined can move into ISAs in a single year this way. Anyone with substantial GIA holdings should run the bed and ISA calculation every April as part of year-end tax planning.