WealthR / Free tools / Bed-and-ISA Calculator

✦ Free UK calculator · 2026/27 rules

Bed-and-ISA Calculator UK

Selling a holding from your General Investment Account and rebuying it inside an ISA moves it out of capital gains tax and dividend tax for good — at the cost of a CGT bill today. This calculator shows you the upfront CGT bill, the long-term tax saving, and the year your future self breaks even — in pounds and pence, using current 2026/27 UK tax rules.

Your Bed-and-ISA situation

All inputs in £ unless marked. Updates as you type.

Holding value today ?

Original cost basis ?

ISA allowance remaining (this tax year) ?

CGT allowance already used ?

Your income tax band ?

Annual return assumption ?

Of which dividend yield ?

Years held going forward ?

Amount you can Bed-and-ISA

£20,000

Limited by ISA allowance

CGT bill on disposal

£600

£3,000 of gain after allowance · 24%

Lifetime tax saved (est.)

£8,200

Over 20 years, vs leaving in GIA

Break-even year

Year 2

When tax saving exceeds CGT bill

Yes — Bed-and-ISA looks worth it.

Your CGT bill on disposal is small relative to the long-term tax savings inside an ISA. Over 20 years you'd save roughly £8,200 in tax — a lot more than the £600 cost upfront.

ⓘ Estimates use HMRC 2026/27 rates: CGT 18%/24%, dividend allowance £500, dividend tax 10.75% / 35.75% / 39.35% by band. Calculations assume the GIA equivalent realises gains via periodic rebalancing and the ISA does not. This is a planning aid, not personal tax advice — consult an authorised adviser before acting.

✦ The full picture

What is Bed-and-ISA, and why does it matter?

If you hold investments in a General Investment Account (GIA) — the unwrapped account most UK platforms default you into when you've used up your ISA — every penny of growth, every dividend, and every disposal is potentially taxable. Inside a Stocks and Shares ISA, none of it is. Bed-and-ISA is the legal, HMRC-recognised process of selling a GIA holding and rebuying it inside your ISA on the same day, locking those holdings into the tax-free wrapper for the rest of their life.

ISA allowances and capital gains rules both move at fiscal events. The next is the Autumn Budget on 28 October 2026 — I keep a running note of what’s confirmed and what’s still only on the table.

The "bed" comes from the older "bed and breakfast" tactic — selling a holding before the tax year ends and rebuying it shortly after to refresh your cost basis. HMRC closed that loophole in 1998 with the 30-day rule. Bed-and-ISA still works because the rebuy happens inside a different legal wrapper — your ISA is treated as a separate beneficial owner for tax purposes. Same security, same broker, same day — completely legitimate.

New for 2026/27: dividend tax rose two points in April 2026 — see what your GIA dividends now cost with the dividend tax calculator, then come back here for the fix.

What you actually save

Three things stop being taxable the moment your holding is inside an ISA:

Capital gains tax on any future sale — 18% or 24% on shares above the £3,000 annual exempt amount.
Dividend tax on income paid by the holding — 10.75% / 35.75% / 39.35% depending on your income band, on anything above the £500 dividend allowance.
Income tax on bond interest, REIT distributions, and similar income inside the ISA wrapper.

The longer the holding stays inside the ISA, the more it compounds free of HMRC drag. For a £20,000 holding throwing off a 2% dividend yield to a higher-rate taxpayer, that's roughly £400 of dividend income each year — about £135 of avoided tax annually, before you even count CGT savings on rebalancing.

The trade-off

Bed-and-ISA crystallises a disposal for CGT purposes. If your gain on the sold portion is bigger than your remaining annual exempt amount (£3,000 for 2026/27), the excess is taxed today at 18% or 24%. The whole question is whether tomorrow's tax savings outweigh today's tax bill — which is exactly what the calculator above answers.

Why investors don't always do it

Three reasons:

Brokerage fees. Some platforms charge for the disposal and re-purchase. Most modern UK brokers (Trading 212, InvestEngine, Vanguard, AJ Bell with their offer, iWeb) make this cheap or free.
Bid-offer spread. If you sell and rebuy a thinly-traded fund or share, you might lose a small amount on the spread — usually a non-issue for ETFs and large funds.
The CGT bill itself. If you've held a position for years and built a six-figure unrealised gain, doing the whole position in one tax year creates a disproportionate bill. The fix is staging — Bed-and-ISA in chunks across multiple tax years to repeatedly use the £3,000 exempt amount.

Timing — when in the tax year to act

The UK tax year runs 6 April to 5 April. Two practical considerations:

Your ISA allowance resets on 6 April. Any unused allowance at midnight on 5 April is gone forever — so investors with leftover allowance often Bed-and-ISA in late March to use it.
Most platforms have an internal Bed-and-ISA cut-off a few working days before 5 April to allow the trade to settle. Plan for around 25 March to be safe.

If you're staging across multiple tax years, you can Bed-and-ISA on 5 April and again the next day on 6 April — using two years' worth of CGT allowance and ISA capacity in 24 hours.

Common variations

Bed-and-SIPP — same idea, but selling and contributing the proceeds into a Self-Invested Personal Pension. You get UK pension tax relief on the contribution (basic-rate added at source, higher/additional rate claimed via Self Assessment). The trade-off is you can't access the money until age 57+ (rising).
Bed-and-spouse — transfer the holding to a spouse or civil partner (a no-gain-no-loss transfer for CGT) so they can use their own annual exempt amount and ISA allowance. Effectively doubles a couple's tax-free capacity.
Bed-and-LISA — Bed into a Lifetime ISA up to £4,000/year. You get a 25% government bonus on contributions, but the LISA money is locked until age 60 (or first home purchase under £450k).

When it's not worth doing

You'd trigger a five-figure CGT bill and have less than five years before the position would otherwise stay flat or be sold anyway.
The holding pays no dividends and you don't intend to rebalance for decades — the deferred CGT may be worth more than the wrapper.
You expect to be a non-UK tax resident in the year of the future sale, and that jurisdiction won't tax UK gains.

For most UK investors, none of these apply, and the calculator will quickly show whether the maths supports the move.

✦ How the calculator works

Methodology

Calculate the disposal gain

Gain = Holding value − Cost basis. We assume the entire holding has the same average cost basis (your section 104 pool).

Apply the CGT annual exempt amount

Taxable gain = Gain − (£3,000 − allowance already used). 2026/27 annual exempt amount is £3,000.

Apply your CGT rate

Basic-rate taxpayers pay 18% on shares above the allowance; higher and additional rate pay 24%. (Residential property uses different rates — not modelled here.)

Cap by ISA allowance

You can only Bed-and-ISA up to your remaining annual ISA allowance (max £20,000 across all ISAs for 2026/27).

Project forward — GIA scenario

Annual dividend tax above the £500 dividend allowance, plus periodic rebalancing CGT. Compounds over the years held.

Project forward — ISA scenario

Same growth, zero tax drag. The difference between the two future values is your lifetime tax saving.

Find break-even

The first year in which cumulative ISA tax savings exceed the upfront CGT cost — this is your payback horizon.

✦ Common questions

Bed-and-ISA FAQ

What is Bed-and-ISA?

Bed-and-ISA is a process where you sell investments held in a General Investment Account (GIA) and immediately repurchase them inside a Stocks and Shares ISA. This shelters all future growth, dividends, and disposals from UK income tax and capital gains tax. The "sale" counts as a disposal for CGT purposes, so you may owe CGT on any gain above your annual exempt amount (£3,000 for 2026/27).

Do I have to pay CGT when I Bed-and-ISA?

Yes — selling the GIA holding is a disposal, even though you immediately rebuy inside the ISA. If your gain on that disposal exceeds your remaining CGT annual exempt amount (£3,000 for 2026/27), the excess is taxed at 18% (basic rate) or 24% (higher/additional rate) for shares and funds — the rates that have applied since 30 October 2024. Many investors stagger Bed-and-ISA across multiple tax years to use the allowance each year and avoid a one-off CGT bill.

Is Bed-and-ISA worth it?

It depends on two figures: the CGT due on the disposal today, and the tax you would otherwise pay on that holding in future. Inside an ISA, dividends and gains are free of UK tax for as long as the money stays there, with no reporting. The calculator above puts both numbers side by side for your own figures and shows the year they cross.

What is the 30-day rule and does it apply?

The 30-day "bed and breakfast" rule says you can't sell shares and rebuy them in your own name within 30 days without HMRC matching the disposal. The rule does not bite when the rebuy is inside an ISA, because ISA holdings sit outside capital gains tax altogether — which is what makes the technique work. You can sell in your GIA and rebuy the same security inside your ISA on the same day.

How much can I Bed-and-ISA each tax year?

You're limited by your annual ISA allowance, which is £20,000 for 2026/27 across all your ISAs combined (Stocks & Shares, Cash, Lifetime ISA up to £4,000, Innovative Finance). If you've already paid into an ISA this tax year, only the unused portion is available for Bed-and-ISA. There's no separate Bed-and-ISA cap.

When is the deadline?

The UK tax year runs from 6 April to 5 April. Bed-and-ISA must be completed by 5 April to use that year's ISA allowance — and most platforms have an internal deadline a few working days earlier (typically late March) to allow time for the trade to settle. Allowances do not roll over.

Can I Bed-and-ISA inside a Lifetime ISA or Junior ISA?

You can Bed-and-ISA into a Lifetime ISA, but the LISA cap is £4,000/year (counting toward your £20,000 overall ISA allowance), and you'll need to be aged 18–39 to open one. Junior ISAs belong to the child, so you can't Bed-and-ISA your own holdings into one — but you can gift cash and the child can hold investments inside their JISA.

What about same-day matching?

Same-day matching applies to disposals matched against acquisitions in the same name on the same day. Because the repurchase happens inside an ISA, outside the CGT regime, same-day matching does not apply — your CGT calculation uses your section 104 holding pool average cost basis, not the rebuy price.

Should I Bed-and-ISA losses?

If a holding is at a loss, selling crystallises that loss and you can use it against current-year or carried-forward gains — but only if you formally claim it within four years. Re-buying inside an ISA breaks the chain for future loss matching. For most investors this is fine; for active traders it's worth modelling carefully.

Does WealthR track Bed-and-ISA for me?

Yes, in part. WealthR Pro's Tax Year Optimiser lists the holdings in your general account (and any physical assets) that show a gain, once you have entered what you paid for them, and groups them against this tax year's CGT annual exempt amount. It also shows an estimate of the ISA allowance you have left. It does not know about gains you have realised elsewhere this year, and it does not record the sale for you.

Want this baked into your full plan?

WealthR Pro's Tax Year Optimiser lists the holdings in your general account that show a gain, grouped against this year's CGT allowance, with an estimate of the ISA allowance you have left. Enter what you paid for each holding and it works from your own figures. Pro has a 7-day free trial.

Try the full app → More free calculators