ISA vs GIA

See the tax saving from using your ISA

ISA Advantage

£46,290

Tax saved over 20 years

ISA Final

£282,624

GIA Final (after tax)

£236,334

Dividend Tax

£8,511

CGT on Disposal

£34,211

Quick context

Read full guide: ISAs Explained →

£20k/year per person, no income tax, no dividend tax, no CGT — ever. The allowance resets every 6 April and doesn't carry forward.
S&S ISA for 5+ year investing; Cash ISA only useful if your interest exceeds the Personal Savings Allowance.
Order of priority: full employer pension match → max ISA → top up pension. Exception: 60% taper band (£100-125k) where pension wins.

Stress test

What if the world changes? Toggle a scenario.

simulator

New isa advantage

£46,290

Δ vs baseline

+£0

Real value 1yr out

£45,161

@ 2.5% CPI

Today£46,290

Now£46,290

Current plan. Scenario figures are illustrative — they scale your current calculation rather than re-running every band. Useful for direction, not for filing.

Outcome

ISA (tax-free)

£282,624

GIA before tax

£279,056

− Dividend tax

£8,511

− Capital Gains Tax

£34,211

GIA net

£236,334

Bottom line: Using an ISA saves you £46,290 over 20 years.

Watch & learn

YouTube · Damien Talks Money

ISA vs GIA: Tax Comparison

A short, plain-English walkthrough relevant to this page. We curate from trusted UK personal finance creators.

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