GOV.UK article “Donating to charity: Gift Aid” explains that Gift Aid allows charities (and CASCs) to claim an extra 25p for every £1 donated when donors make a Gift Aid declaration, details eligibility, declaration and record-keeping requirements, and explains higher-rate taxpayer reclaim and payroll-giving differences; this authoritative guidance is included in Part 2, Chapter “Philanthropic Giving,” Sub‑Chapter “Financial Vehicles of Philanthropic Giving” to show how tax relief functions as a financial vehicle that boosts charities’ income and affects donors’ net cost—informing tax‑efficient philanthropic strategies and investors’ net‑cost calculations (Footnote: Page 84).