ISAs: a complete tax shelter

Place the ISA precisely on the map from the income-tax fundamentals lesson: ISA income is EXEMPT — the third and strongest of the three mechanisms. Not a deduction, not a 0% band: interest, dividends and gains inside the wrapper never enter the tax computation at all. That exact wording earns marks, because the consequences are what the exam tests: ISA income doesn't use the personal savings allowance or dividend allowance, doesn't consume the CGT annual exempt amount, doesn't count toward adjusted net income for the personal allowance taper, and never appears on a tax return. Compare interest covered by the PSA — taxed at 0% but still counted everywhere — and the distinction stops being pedantic. Now the boundaries of the shelter, each one a question in its own right. It cuts both ways: a loss inside an ISA is a dead loss, never usable against outside gains. It ends at the right border: the ISA shelters income and gains, and does NOTHING for inheritance tax — the full value sits in the estate (the seven-year clock belongs to gifts, not wrappers). On death it unwinds gently: the account keeps its tax-free status while the estate is administered, and the surviving spouse or civil partner gets an additional permitted subscription equal to the ISA's VALUE — on top of, and uncapped by, their own annual allowance. And its conveniences are rule-bound: transfers between providers never touch the current year's subscription limit (transfers are not subscriptions), while flexible withdrawal-and-replacement exists only where the provider offers it, and only back into the same ISA.