Personal allowance taper and the personal savings allowance

Everyone starts with a personal allowance of £12,570 — the slice of income taxed at 0%. Once a client's adjusted net income goes above £100,000, that allowance is reduced by £1 for every £2 of income over the threshold, all the way down to nothing once it's fully used up. It's easy to forget this taper happens automatically — nobody has to elect into it, and there's no cliff-edge warning; the allowance just quietly shrinks. The personal savings allowance is a separate thing entirely: it's a band of savings interest taxed at 0%, not a deduction from income. It's £1,000 for a basic-rate taxpayer, £500 for a higher-rate taxpayer, and disappears entirely once someone is an additional-rate taxpayer — a common trap is assuming the higher-rate figure still applies at the very top of the income scale.