Tax year 2026/27

ISA / GIA Optimiser

Quantify compounding friction from dividend and CGT in a GIA versus a tax-free ISA.

Opening lump£20,000

Monthly contribution£500

Horizon20 years

Gross annual return7.0%

Dividend yield2.0%

Annual turnover (realised CGT)10%

Annual contributions exceed the £20,000 Stocks & Shares ISA limit. The ISA line is a wrapper-capacity illustration, not a legal contribution path.

ISA ending

£342,757

GIA after exit CGT

£319,390

Tax drag

£23,368

6.8%

Contributions

£140,000

ISA gain

£202,757

GIA gain

£179,390

ISA vs GIA

Emerald: ISA. Amber: GIA after annual tax.