Child support (often called child maintenance) is the regular financial provision a parent makes for a child’s living costs when parents live apart. In Great Britain and Northern Ireland the term sits within the statutory child maintenance scheme (Child Support Act 1991 and regulations), administered by the Child Maintenance Service (CMS). The CMS calculates maintenance by formula, broadly using the paying parent’s gross income, number of qualifying children, any shared care, and other dependants, and can collect and enforce (e.g., deduction from earnings or bank accounts).Across England & Wales and Scotland the statutory scheme has primacy over court‑ordered periodical payments, with limited exceptions. Courts can deal with capital/other needs: Schedule 1 Children Act 1989 (E&W) and aliment orders in Scotland allow lump sums, property settlement, school fees, and “top‑up” orders where income exceeds the CMS maximum. Parties may agree maintenance; a court order for periodical child maintenance can generally be displaced by a subsequent CMS calculation after 12 months.In Northern Ireland, an equivalent CMS operates under the Child Support (Northern Ireland) Order 1991, with similar rules.In Ireland (Republic), there is no CMS. “Maintenance” is court‑based under the Family Law (Maintenance of Spouses and Children) Act 1976 (as amended), determined by means and needs, with enforcement including attachment of earnings.