Every time you buy a UK-listed share electronically, 0.5% of the purchase price disappears as Stamp Duty Reserve Tax. Your broker deducts it automatically — so automatically that most investors forget it exists. But it has a direct impact on your CGT calculation, and forgetting to include it means you’re overpaying tax.
How SDRT works
Buy £10,000 of Barclays shares → SDRT of £50 is deducted. Your actual cost for CGT purposes is £10,050. When you sell, that extra £50 reduces your taxable gain.
SDRT is an allowable cost of acquisition under TCGA 1992 s.38(1)(b). It enters your Section 104 pool alongside the share price and broker commission. The gov.uk guidance on buying shares confirms the 0.5% rate.
When you don’t pay SDRT
US shares: No SDRT. Apple, Tesla, NVIDIA — all SDRT-free. This applies to all non-UK shares.
Irish-domiciled ETFs: No SDRT. Since most popular ETFs (Vanguard VWRL, iShares MSCI World, etc.) are domiciled in Ireland, you don’t pay it. See our ETF tax guide.
Most AIM shares: Companies listed on AIM (the London Stock Exchange’s junior market) are generally exempt from SDRT, as part of the government’s effort to encourage investment in smaller companies. The London Stock Exchange’s AIM page lists current members.
ISA purchases: You still pay SDRT inside an ISA (it’s deducted at the point of purchase), but since ISA gains are tax-free, the cost basis doesn’t matter for CGT purposes.
Practical impact
Over years of regular investing in UK shares, SDRT adds up:
| Total UK share purchases | SDRT paid | CGT saving at 18% | CGT saving at 24% |
|---|---|---|---|
| £10,000 | £50 | £9 | £12 |
| £50,000 | £250 | £45 | £60 |
| £200,000 | £1,000 | £180 | £240 |
Not life-changing amounts — but it’s money you’ve already paid. Failing to include it in your cost basis is leaving a legitimate deduction on the table.
Does your broker report it?
Trading 212 and Freetrade typically include SDRT in the total transaction amount — so if your CSV shows a “total cost” figure, the stamp duty is already baked in. But check: some brokers show the share cost and stamp duty as separate line items.
For US brokers like Robinhood UK and Tastytrade, SDRT isn’t relevant because you’re trading US securities.
TaxBull accounts for SDRT in the cost basis calculations where the broker CSV reports it. For multi-broker portfolios, make sure each broker’s stamp duty is captured correctly.
This is general information only. SDRT rates are set by HMRC and could change. Check gov.uk/tax-buy-shares for current rates.
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