Windsor Framework Duty 2026: Green Lane vs Red Lane for Northern Ireland

The Windsor Framework restructured the UK-EU goods movement regime after the Northern Ireland Protocol proved unworkable. In force since October 2023, refined through 2024 to 2025 implementation, and now combined with ICS2 Phase 3 (January 2026), the framework determines whether goods moving from Great Britain to Northern Ireland flow with minimal friction or trigger full EU customs procedures.

This guide covers the green-lane / red-lane categorization, the UK Internal Market Scheme (UKIMS) registration, the ICS2 January 2026 change, and worked examples for typical retailer and B2B shipments.

The Windsor Framework in summary

After Brexit (January 2021), Northern Ireland uniquely remained in the EU Single Market for goods. This created a customs border within the UK between Great Britain and Northern Ireland (the GB-NI line). The original Northern Ireland Protocol applied full EU customs procedures to most GB-NI movements, generating significant friction.

The Windsor Framework (February 2023 agreement, October 2023 in force) introduced a green-lane / red-lane split:

• Green lane: goods staying in the UK internal market. Simplified declaration, no EU duty, no EU tariff, no EU CBAM, no EU VAT.
• Red lane: goods at risk of onward movement into the EU. Full EU customs procedures, EU duty, EU tariff, EU CBAM, EU VAT.

Green-lane eligibility requires:

1. The trader is registered in the UK Internal Market Scheme (UKIMS).
2. The goods are clearly destined for use or sale in Northern Ireland by the end consumer or business user.
3. The goods are not in a "high-risk" category requiring red-lane handling (regulated goods, certain agri-food).

UK Internal Market Scheme (UKIMS)

UKIMS is the gatekeeper for green-lane access. Traders register with HMRC and commit to:

• Maintaining records sufficient to demonstrate that green-lane goods stayed in the UK internal market.
• Submitting periodic declarations.
• Compliance with HMRC audit on green-lane status.

Registration is free. Most UK retailers, wholesalers, and B2B suppliers with regular GB-NI trade have registered. Without UKIMS, all GB-NI movements default to red-lane procedures.

Worked example: UK retailer ships to Belfast store

A UK home goods retailer (registered in UKIMS) ships 100,000 GBP of HTS 9404 mattresses from a Manchester warehouse to a Belfast store for retail sale.

Green lane treatment:

Effective rate 20 percent (recoverable UK VAT for VAT-registered business). Same treatment as if the goods stayed entirely within England. The Windsor Framework wipes the EU layer.

Worked example: Wholesaler ships to NI distributor with EU re-export risk

A UK distributor (UKIMS registered) ships 200,000 GBP of HTS 7308 steel structures from Birmingham to a Belfast distributor who may onward ship to a Republic of Ireland customer.

Red lane treatment (goods at risk):

The red-lane treatment generates much higher landed cost when the goods are at risk of EU onward movement. The distributor in this case might choose to:

1. Confirm the goods will stay in NI and use green lane (lower cost).
2. Accept red lane and pass the cost to the eventual ROI customer.
3. Reroute the eventual ROI customer through a direct GB-ROI shipment (different customs procedures, but no Windsor Framework involved).

The choice depends on volume, customer preferences, and operational simplicity.

What changed in January 2026 with ICS2

The EU's Import Control System 2 (ICS2) Phase 3 entered force January 1 2026. ICS2 is the EU's pre-arrival cargo safety and security data system. The expansion applied to:

• Road cargo entering the EU.
• Rail cargo entering the EU.
• Postal and express consignments at all transport modes (already in earlier phases).

For Northern Ireland-bound red-lane goods, this means:

• Additional Entry Summary Declaration (ENS) filing pre-arrival.
• Earlier data submission timing (typically 1 hour before arrival for road, 2 hours for rail).
• Risk-based examination targeting.

Green-lane goods are exempt from ICS2 ENS filing under the Windsor Framework simplifications. This is one of the most operationally significant benefits of green-lane eligibility.

Documentation

For green-lane movements:

• UKIMS authorization number.
• Simplified declaration with HTS line and value.
• Internal records demonstrating UK internal market destination.

For red-lane movements:

• Full EU customs declaration.
• ICS2 ENS pre-arrival data.
• CBAM declaration if applicable.
• EU VAT declaration if applicable.
• EU SPS certificates for agri-food.

What businesses should do

1. Register in UKIMS if not already. Free, fast, gates green-lane access.

2. Identify which goods can legitimately use green lane. Most retail-to-consumer and B2B-to-NI-user shipments qualify.

3. Set up dual-channel logistics for goods at risk of EU onward movement. Red-lane procedures benefit from advance preparation. Last-minute red-lane filings have higher error rates and exam risk.

4. For CBAM-scope goods (steel, aluminum) at risk of EU re-export, model the CBAM cost. This is often the largest single layer in the red-lane stack.

5. Watch the post-2026 evolution. EU and UK have committed to ongoing simplification of the GB-NI border. Additional changes are likely as ICS2 and CBAM both mature.

Run your GB-NI shipment now

The LandedFees calculator handles the Windsor Framework green-lane / red-lane logic, the UKIMS eligibility flag, the EU MFN if red lane, the CBAM stack for steel and aluminum, and the UK VAT vs EU VAT treatment.

Calculate a GB to NI shipment

Citations

• Windsor Framework agreement: https://www.gov.uk/government/publications/the-windsor-framework
• UK Internal Market Scheme (UKIMS): HMRC guidance
• EU ICS2 Phase 3 January 2026: https://taxation-customs.ec.europa.eu/customs-4/customs-security/import-control-system-2-ics2_en
• CBAM regulation (EU) 2023/956
• Northern Ireland Protocol original text (superseded by Windsor Framework): EUR-Lex