The Windsor Framework, agreed between the UK Government and the European Commission in February 2023, significantly modified the operation of the Northern Ireland Protocol that had governed GB–NI trade since Brexit. The Framework introduced the Green Lane / Red Lane system, which distinguishes between goods destined to stay in Northern Ireland (Green Lane) and goods at risk of moving into the Republic of Ireland and the EU single market (Red Lane). For businesses trading between Great Britain and Northern Ireland, the Windsor Framework represents a significant improvement in the practical trading position — but the compliance requirements remain substantive and must be properly understood. The Green Lane System Goods moving from Great Britain to Northern Ireland that are destined to remain in Northern Ireland can use the Green Lane, which involves significantly reduced documentation and declaration requirements compared to the Red Lane (EU import procedure) requirements. To use the Green Lane, businesses must be registered as Trusted Traders under the UK Internal Market Scheme (UKIMS). UKIMS registration requires: - UK establishment - Evidence of legitimate commercial operations in GB–NI trade - No serious or repeated criminal offences or infringements For UKIMS-registered traders, the Green Lane process involves: - An Internal Market Movement Information (IMMI) declaration — a simplified data set compared to a full customs declaration - No customs duty - No presentation to inspection facilities at Northern Ireland ports for most goods The Red Lane Goods that are at risk of moving into the EU single market — typically goods intended for onward sale to the Republic of Ireland or other EU member states — must use the Red Lane. Under the Red Lane, EU import procedures apply, including: - Full customs declarations - Payment of EU customs duty - Sanitary and phytosanitary controls for food, plants and animals For businesses that genuinely trade only into the NI market, UKIMS registration and Green Lane use should be achievable. For businesses where goods may move between NI and ROI, Red Lane compliance is the appropriate route. Excise Goods Excise goods (alcohol, tobacco, fuel) are subject to separate arrangements and do not benefit from the Green Lane simplifications in the same way as general goods. Specific HMRC guidance should be consulted for excise movements. Parcel Trade A separate parcel regime applies to small parcels sent by individuals (not businesses) from GB to NI, with further simplifications for consumer-to-consumer movements. VAT Northern Ireland remains within the UK VAT area for goods (unlike the EU VAT area). GB–NI trade does not attract customs VAT. However, NI businesses selling goods to EU customers operate within the EU VAT rules for those transactions. Key Practical Steps for GB–NI Traders 1. Apply for UKIMS registration if you move goods from GB to NI that are intended to remain in Northern Ireland. 2. Review your customer base to determine whether any goods are at risk of onward movement to the Republic of Ireland (which would require Red Lane treatment). 3. Ensure your logistics and systems are set up to generate IMMI declarations for Green Lane movements. 4. Review the UKIMS terms — registration can be suspended if compliance standards are not maintained. 5. Seek specialist advice if your supply chain includes goods crossing the NI–ROI border. Looking Ahead The Windsor Framework has improved the GB–NI trading position materially compared to the original Protocol, but the arrangements remain more complex than pre-Brexit intra-UK trade. HMRC and the EU are both continuing to develop the technical infrastructure supporting these arrangements, and businesses should monitor updates to HMRC guidance regularly. Conclusion For businesses with significant GB–NI trade flows, UKIMS registration and Green Lane compliance is the most important practical step to take. The compliance system is materially better than the original Protocol arrangements, and most legitimate GB–NI traders should be able to operate efficiently under the Green Lane system with appropriate preparation and systems support.