For businesses moving goods between Great Britain and Northern Ireland, navigating trade post-Brexit can still feel complex. While there are now simplified procedures designed to support trade within the UK internal market, businesses must still decide which customs route is right for them. In most cases, this means choosing between using the simplified arrangements available under the Windsor Framework, supported by the Trader Support Service (TSS), or submitting a traditional full import declaration.
Understanding the differences between these approaches is key to balancing cost, compliance and administrative workload. While the Windsor Framework was designed to make trade within the UK internal market easier, many businesses are still unclear on how it works in practice, what role TSS and the UK Internal Market Scheme (UKIMS) play, and when a full import entry may be the better option.
In this guide, we explain both customs routes, break down the terminology, and help you understand the options available so you can trade with Northern Ireland with confidence.
Table of Contents
What is the Windsor Framework?
The Windsor Framework is an agreement between the UK and EU designed to make the movement of goods from Great Britain to Northern Ireland more efficient.
It was first announced in 2023 to replace the original Northern Ireland Protocol, and was fully implemented as of 2025.
One of its key objectives is to reduce the administrative burden on businesses whose goods are destined to remain in Northern Ireland, rather than entering the European Union, through the introduction of simplified processes for eligible goods.
The framework introduced a number of practical changes, including:
- Simplified processes for eligible goods moving within the UK internal market
- Reduced data requirements for certain declarations
- Streamlined procedures for authorised traders
- Greater clarity around which goods are considered “at risk” of entering the EU
- The introduction of green lane and red lane processes for goods moving from Great Britain to Northern Ireland
For many businesses, these changes have significantly reduced the complexity of moving goods to Northern Ireland. However, businesses must be registered under the UK International Market Scheme (UKIMS) in order to trade under the Windsor Framework.
What is UKIMS?
The UK Internal Market Scheme (UKIMS) is a key component of the Windsor Framework.
It allows authorised businesses to move eligible goods from Great Britain into Northern Ireland under simplified arrangements where those goods are not intended to enter the EU market.
Once approved under UKIMS, businesses can declare qualifying goods as “not at risk” and move them using simplified Internal Market Movement processes. Rather than submitting a full customs declaration for each shipment, businesses only need to provide Internal Market Movement Information, a reduced dataset based on the commercial information already available about their goods. This means less information is required for each movement, helping to reduce administration and simplify compliance.
For organisations regularly trading with Northern Ireland, UKIMS can play an important role in improving efficiency and reducing compliance burdens.
What does “Not at risk” mean in practice?
“Not at risk” goods are goods being moved from Great Britain into Northern Ireland that are not expected to enter the EU. In practice, this generally means goods intended for sale or final use in Northern Ireland, or goods that will remain within the UK internal market rather than being moved onwards into the Republic of Ireland or elsewhere in the EU. Businesses authorised under the UK Internal Market Scheme (UKIMS) can declare eligible goods as “not at risk” and benefit from simplified customs procedures.
Businesses should therefore check the end use before relying on UKIMS. A shipment delivered to a Northern Ireland customer may still fall outside the simplified route if the goods are intended for onward sale into Ireland or another EU market.
Do You Need UKIMS?
While not every business moving goods to Northern Ireland requires UKIMS authorisation, it can offer significant advantages for eligible traders. UKIMS may be particularly beneficial if your business:
- Regularly ships goods from Great Britain to Northern Ireland
- Supplies customers located in Northern Ireland
- Transfers stock between UK sites
- Seeks to minimise the risk of delays caused by customs requirements
Businesses trading with Northern Ireland should review their supply chains carefully to determine whether UKIMS could support more efficient operations.
What is the Trader Support Service (TSS)?
The Trader Support Service (TSS) is a government-funded service created to help businesses comply with customs requirements when moving goods between Great Britain and Northern Ireland. It was originally introduced to support traders following Brexit and continues to play a central role under the Windsor Framework.
TSS is not a customs route in and of itself. Instead, it is a service that helps businesses complete the declarations and processes required to move goods into Northern Ireland. It can complete customs and safety and security declarations on behalf of traders, reducing the need for businesses to interact directly with HMRC customs systems.
For businesses authorised under UKIMS, TSS can also be used to submit the information required for Internal Market Movements. These simplified movements allow eligible “not at risk” goods to move using reduced data requirements rather than a traditional full customs declaration.
In simple terms:
- The Windsor Framework establishes the rules.
- Registering for UKIMS gives eligible businesses access to simplified arrangements.
- TSS helps businesses complete the necessary declarations and processes.
Businesses are still responsible for providing accurate data, maintaining appropriate records and ensuring goods meet the relevant eligibility criteria. As a result, many businesses find that while TSS reduces direct customs costs, it can require greater internal administration than outsourcing a full customs declaration to a customs agent.
What option is right for my business?
When moving goods from Great Britain to Northern Ireland, businesses generally have two options.
The first is to use the simplified procedures available under the Windsor Framework through UKIMS, with declarations often supported by TSS. This route is designed for eligible goods that are considered “not at risk” of entering the EU. By taking advantage of the simplified Internal Market Movement process, businesses can reduce the amount of customs information required and avoid many of the formalities associated with a traditional import declaration.
The second option is to submit a full import declaration. This follows a more traditional customs process and is often used where goods are not eligible for UKIMS simplifications, are considered at risk of moving into the EU market, or where a business simply prefers to manage movements through a customs intermediary. Although this route typically involves customs brokerage fees and more extensive declaration requirements, some businesses find it operationally simpler because much of the customs administration is handled externally.
The right approach depends on your business, your products and the nature of your supply chain.
For businesses that regularly supply customers in Northern Ireland and whose goods qualify as “not at risk”, UKIMS and the simplified Windsor Framework arrangements can offer a more cost-effective solution. Reduced declaration requirements and access to the free Trader Support Service can help lower customs costs while supporting efficient trade within the UK internal market.
However, cost is only one part of the decision. Businesses using the simplified route must still ensure they understand the eligibility requirements, maintain supporting records and provide accurate information for each movement. For organisations with complex product ranges, limited internal customs knowledge or resource constraints, a full import declaration completed through a customs intermediary may be the more practical option, despite the additional expense.
Ultimately, what works well for one business may not be the right fit for another. The key is understanding the options available, assessing how they align with your operations, and ensuring your customs processes remain compliant from the outset.
Taking the complexity out of customs
Experienced customs professionals can help businesses navigate requirements, identify opportunities for simplification, and reduce the risk of costly errors. Our in-house customs team has years of experience staying up to date with changing customs requirements, helping businesses keep goods moving efficiently in and out of the UK.
Whether you’re looking to complete a full import declaration, or use the Trader Support Service (TSS), we can help you navigate the customs requirements, and ensure your shipments remain compliant.
If you would like support moving goods to Northern Ireland, we’re here to help.
