A tariff is a schedule of fixed charges or rates, most commonly referring in legal practice to customs duties imposed on imported or exported goods. Lawyers encounter tariffs in customs, international trade, tax, regulatory and commercial contract work, where they affect pricing, supply chains and compliance obligations.In the UK (including England & Wales, Scotland and Northern Ireland), tariff structures for customs duties are primarily set out in statute and detailed regulations, historically under EU law and now under the UK’s independent customs and trade regime. In Ireland, tariffs are determined under EU customs law and the EU Common External Tariff. Northern Ireland is subject to specific post‑Brexit arrangements, including the Windsor Framework, which can result in different tariff treatment compared with Great Britain.“Tariff” is also used more broadly to describe structured price lists or standardised charges (for example, in utilities, transport and professional services), usually governed by contract, regulatory rules or sector‑specific legislation.In criminal law in the UK, “tariff” can colloquially describe the minimum custodial term before release on parole for certain life sentences, although formal terminology in statute and case law focuses on “minimum terms” rather than “tariffs”.