Forms an integral part of the withdrawal agreement (Article 182, withdrawal agreement), and applies in parallel to the UK-EU trade and co-operation agreement (TCA) (Article 775, TCA).

Sets out arrangements to avoid a hard land border between Ireland and Northern Ireland which require Northern Ireland to remain aligned to specified EU single market and customs rules (Articles 5-10, Northern Ireland Protocol). These include specified provisions of EU law relating to goods and customs, VAT and excise on goods, agriculture and the environment, the single electricity market, and state aid.

Requires the UK to provide opportunities for the Northern Ireland Assembly to decide to discontinue the application of Articles 5 to 10 (Article 18, Northern Ireland Protocol). The first opportunity to make such a decision arises just under four years after the end of the transition period. Articles 5 to 10 would cease to apply two years after a decision to discontinue.