CGT Glossary — Every Term UK Investors Need to Know

Capital Gains Tax has its own vocabulary. This glossary defines every term you’re likely to encounter, with links to our detailed guides where they exist.

A

Allowable costs — Expenses you can deduct from your gain. Includes broker commissions, stamp duty, legal fees, and FX conversion costs. Defined in TCGA 1992 s.38.

Annual Exempt Amount (AEA) — The tax-free CGT allowance. £3,000 for individuals in 2025/26 and 2026/27. Can’t be carried forward. See our rates guide.

Accumulating fund — An ETF or fund that reinvests dividends internally rather than paying them out. May trigger Excess Reportable Income. See our ETF guide.

B

Bed and breakfast — The 30-day rule. Selling shares and rebuying within 30 days. Named after the original strategy of selling on Friday and rebuying on Monday, which was blocked in 1998.

Bed and ISA — Selling shares in a GIA and rebuying inside an ISA. Legal and effective — ISA repurchases don’t trigger the 30-day rule.

Bed and spouse — Transferring shares to your spouse (at no gain/no loss) for them to sell. Uses their CGT exemption and potentially lower tax band. See our gifting guide.

C

Chargeable asset — Any asset subject to CGT when disposed of. Includes shares, property, crypto, options. Defined broadly in TCGA 1992 s.21.

Chargeable gain — The taxable profit from disposing of a chargeable asset.

Contract note — The formal confirmation from your broker for each trade. Your primary evidence for HMRC.

D

Disposal — Selling, gifting, swapping, or otherwise getting rid of an asset. Triggers CGT. See our beginner’s guide.

Disposal proceeds — What you received (or are treated as receiving) for the asset.

Dividend allowance — First £500 of dividends is tax-free (2025/26). Separate from CGT. See our dividend tax guide.

E

ERI (Excess Reportable Income) — Income from offshore accumulating funds that you haven’t received as cash but must declare as income. Also added to your S104 pool cost.

F

FIFO (First In, First Out) — US cost basis method. Does not apply in the UK. HMRC uses pooling.

FSCS — Financial Services Compensation Scheme. Protects up to £85,000 if your broker fails.

G

GIA (General Investment Account) — A taxable investment account. Gains are subject to CGT. Compare with ISA.

H

HMRC exchange rates — Official monthly rates for converting foreign currency to GBP. Published on the Trade Tariff service.

I

ISA — Individual Savings Account. Gains inside an ISA are completely exempt from CGT. £20,000 annual allowance.

L

Loss relief — Using capital losses to offset gains. Current-year losses are used in full; brought-forward losses are used only to reduce gains to the AEA.

M

Matching rules — HMRC’s mandatory share identification rules. Same-day → 30-day → S104 pool.

MTD (Making Tax Digital) — HMRC’s digital reporting programme. Doesn’t yet apply to CGT directly.

N

No gain, no loss — Tax treatment of transfers between spouses. The recipient inherits the original cost basis. See gifting shares.

O

Option (traded) — A chargeable asset under TCGA s.144. Gains/losses reported in SA108 Boxes 14-22.

P

Pool — See Section 104 pool.

R

Reporting fund status — Determines whether gains on offshore ETFs are taxed as capital gains (good) or income (bad).

S

SA108 — The Capital Gains Summary supplementary page of the self-assessment tax return.

Section 104 pool — The weighted-average cost pool for shares. All shares of the same class in the same company are pooled together.

SDRT — Stamp Duty Reserve Tax. 0.5% on purchases of UK shares.

T

TCGA 1992 — Taxation of Chargeable Gains Act 1992. The primary legislation governing UK CGT.

Temporary non-residence — The 5-year rule that catches people who leave, sell assets, and return.

W

W-8BEN — IRS form that reduces US dividend withholding from 30% to 15% for UK residents.

Wash sale — US rule. Does not apply in the UK.

Calculate your CGT with all these rules applied correctly — upload your broker CSV to TaxBull.

Definitions are simplified for clarity. See linked guides and HMRC sources for full detail.