UKIMS in GB→NI trade — what it is, who can use it and how to register

Trade between Great Britain (England, Scotland and Wales — GB) and Northern Ireland (NI) was for many years simply domestic trade. After Brexit and the introduction of the Northern Ireland Protocol, the customs relationship between GB and NI became one of the most complex political and commercial issues in Europe. The Windsor Framework, signed in February 2023, introduced a solution in the form of a new mechanism — the UK Internal Market Scheme, or UKIMS for short. This tool allows eligible GB businesses to send goods to Northern Ireland without full customs formalities, provided those goods are destined for the UK market and are not being exported onwards to the Republic of Ireland and then to the EU single market. For Polish businesses with a presence or branch in the UK, UKIMS has direct operational significance — it determines how many formalities you must complete when shipping goods from a warehouse in England to a customer in Belfast. This article explains what UKIMS is, who can use it, how registration works and what it means in practice.

What UKIMS is and where it came from

UKIMS (UK Internal Market Scheme) is a preferential mechanism introduced by the Windsor Framework (Windsor Agreement, February 2023), which came into full effect in 2024. It replaced the earlier Trader Support Service and other transitional-period support mechanisms.

The purpose of UKIMS is precise: to allow GB businesses to trade with Northern Ireland as if it were domestic trade — without customs declarations and without duty — for goods that will genuinely remain on the UK market and will not enter the EU single market.

Legal context: Northern Ireland remained, after Brexit, subject to certain EU rules on goods (though not services). This means that goods from GB entering NI could in principle pass on to the Republic of Ireland (RoI) and from there into the EU market — bypassing the EU customs border. UKIMS is the mechanism that allows HMRC and the EU authorities to monitor that flow and separate goods destined for the UK market from goods considered "at risk" (of entering the EU market).

How UKIMS differs from previous mechanisms

Before UKIMS there were several overlapping temporary support systems that were complex and short-term. UKIMS is their successor and a simplification:

Scheme	Period	Status
Trader Support Service	2021–2023	Ended
Staged Customs Controls	2021–2023	Ended
Windsor Framework Green Lane	From 2024	Active — UKIMS is the foundation
UKIMS	From 2023 (registrations)	Active

The key simplification: under UKIMS a GB business sending goods to NI does not submit import declarations for each individual consignment. Instead, it declares once (at registration and in supplementary reports) that the goods are destined for the UK market. This is the so-called "Not at Risk" declaration.

Who can register for UKIMS

UKIMS is not available to everyone. HMRC has set precise eligibility criteria:

Mandatory requirements: 1. The business must be registered in the UK (have a UK establishment — a registered office, branch or fixed place of business in the UK) 2. The business must be registered for VAT in the UK (have an active GB VAT number) 3. The business must have a good customs and tax compliance record — no outstanding tax or customs liabilities, no history of serious infringements 4. The goods must be destined for final recipients in the UK (consumers or businesses in NI), and not for onward export to RoI or the EU

Who does not qualify: - Businesses without a fixed establishment in the UK (e.g. a Polish company selling directly from Poland to customers in NI) - Intermediaries and fulfilment houses acting on behalf of businesses that do not meet the criteria - Businesses whose goods are "at risk" — destined to enter the EU market

Special cases: Polish businesses with a branch or subsidiary registered in the UK (e.g. a Ltd company) may be eligible for UKIMS — but it is the UK entity that qualifies, not the Polish entity.

How to register for UKIMS — step by step

UKIMS registration is completed through the HMRC online government portal:

Step 1: Confirm you meet the criteria Check that you have an active GB VAT number, a UK establishment, and no outstanding customs or tax liabilities.

Step 2: Sign in to Government Gateway Use the same government account you use for other HMRC services (VAT, PAYE, CDS).

Step 3: Submit the UKIMS application Complete the online form at gov.uk/guidance/apply-for-the-uk-internal-market-scheme. You will provide company details, your GB VAT number, a description of your business and the types of goods you typically send to NI.

Step 4: Await the decision HMRC typically processes applications within a few weeks. Once approved, you receive a UKIMS number.

Step 5: Use your UKIMS number on shipments Your UKIMS number is included in transport documents and customs entries for GB→NI goods. It signals to UK Border Force and HMRC that the goods are "not at risk".

Step 6: Supplementary reporting As a UKIMS participant you may be required to submit supplementary declarations (supplementary reports) rather than a declaration for each individual consignment.

What you gain by registering for UKIMS

For an eligible business, UKIMS delivers concrete operational benefits:

Zero duty for GB→NI goods Goods sent by a UKIMS-registered business from GB to NI are not subject to duty — even if the goods originate from third countries (e.g. purchased in Poland and sold from a warehouse in England to customers in Belfast).

No per-consignment import declarations Instead of submitting a separate customs declaration for each shipment, the business reports in bulk. This is a significant saving in time and cost for businesses handling hundreds of shipments a month.

Green Lane instead of Red Lane Goods from a registered business travel via the "green lane" — without full customs formalities at the GB/NI border (administratively — physical checks at ports may still apply).

Reduced SPS requirements for agricultural goods in internal trade For goods covered by UKIMS, sanitary and phytosanitary (SPS) inspection requirements are reduced compared with "at risk" goods.

UKIMS limits and restrictions

UKIMS is not a solution for every situation:

Goods "at risk" Goods that a business sends to NI with the intention of onward export to RoI or the EU do not qualify for UKIMS. They must go through the "red lane" with full declarations and potentially duty at EU rates (if the UK goods do not satisfy TCA rules of origin).

Higher-risk goods (special categories) Certain categories of goods are subject to specific rules even within UKIMS — for example, medicines, foodstuffs and veterinary products. These goods may require additional checks or documentation.

Value limits for B2C consignments For consignments to consumers (B2C) from GB to NI, the Windsor Framework introduced a specific Personal Package Limit (discussed in detail in the Windsor Framework article on B2C parcels).

How UKIMS affects Polish businesses operating in the UK

For Polish entrepreneurs running a business in the UK (e.g. through a Ltd company), UKIMS has several practical implications:

1. Warehouse in England, customers in NI — if you run fulfilment from a warehouse in England and have customers in NI, registering for UKIMS can significantly simplify your logistics. Without UKIMS, every consignment to NI formally goes through an import procedure.

2. Marketplaces and UKIMS — if you sell via Amazon FBA from UK warehouses, Amazon may hold its own UKIMS registration or act as a Customs Intermediary. It is worth checking whether Amazon declares UKIMS on your consignments to NI.

3. Importing from Poland to the UK, selling to NI — goods imported from Poland to England (e.g. furniture) and sold to customers in Belfast may benefit from UKIMS, provided your UK company is registered and the goods are destined for the UK market.