Logistics 101

TSS Reference

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A TSS reference (Trader Support Service reference) is a unique ID used by businesses that move goods between Great Britain and Northern Ireland. It's required to complete customs declarations under the Windsor Framework, helping goods move smoothly across the Irish Sea.

What Is the Trader Support Service (TSS)?

The Trader Support Service (TSS) is a free UK Government service that simplifies customs procedures for goods shipped to and from Northern Ireland. It acts as an intermediary, submitting import and export declarations on behalf of traders and ensuring compliance with Windsor Framework customs requirements.

Under the Windsor Framework, which came fully into effect on 1 May 2025, customs declarations are required for goods moving from Great Britain to Northern Ireland. TSS was created to handle these declarations free of charge so businesses don't need their own customs software or broker for GB-NI movements.

Why You Need a TSS Reference

You must have a TSS reference if you:

  • Ship goods from Great Britain to Northern Ireland
  • Receive goods into Northern Ireland
  • Need to complete customs declarations for these movements

Without it, your goods may be delayed or held at customs.

Businesses that trade regularly with Northern Ireland may also want to register for the UK Internal Market Scheme (UKIMS), which allows qualifying goods to be declared as 'not at risk' of entering the EU single market and can reduce customs requirements.

Do You Need an XI EORI?

Yes — to apply for a TSS reference, your business must hold an XI EORI number, which identifies traders operating under Northern Ireland customs procedures. If you don't have one yet, you can apply for an XI EORI on GOV.UK.

See our XI EORI guide for how to apply and when it's needed.

How to Apply

You can register for free and obtain your TSS reference number here: trader-support-service

Frequently Asked Questions

about TSS reference

Understanding tss

A TSS reference is a unique identifier issued to businesses registered with the Trader Support Service. It is used to process customs declarations for goods moving between Great Britain and Northern Ireland, ensuring shipments comply with the Windsor Framework requirements and clear customs without unnecessary delays.
The Trader Support Service is a free UK Government-funded service that helps businesses manage customs declarations for goods entering or leaving Northern Ireland. It acts as an indirect customs representative, submitting import and export declarations on behalf of traders and ensuring compliance with Northern Ireland customs procedures.
TSS was created to support businesses affected by post-Brexit customs requirements for goods moving between Great Britain and Northern Ireland. Under the Windsor Framework, these movements require customs declarations. TSS simplifies this process by handling declarations free of charge on behalf of registered businesses.
Yes. TSS is completely free, funded by the UK Government. There are no registration fees, no usage charges, and no limits on the number of declarations TSS can process on your behalf.

Who needs a tss reference

Any business that ships goods from Great Britain to Northern Ireland, or receives goods into Northern Ireland from Great Britain, needs to be registered with TSS and have a valid TSS reference to complete the required customs declarations.
Generally no. Movements from Northern Ireland to Great Britain are treated as internal UK movements and do not normally require customs declarations or a TSS reference.
No. TSS only applies to movements between Great Britain and Northern Ireland. Domestic shipments within England, Scotland, and Wales do not require TSS.
No. TSS is specifically for GB–NI movements. International shipments to Europe, USA, Asia, or other destinations are handled through standard customs procedures using your GB EORI number.
Yes. Businesses based anywhere in Great Britain or overseas can register for TSS if they move goods to or from Northern Ireland.

Tss and eori

Yes. To register with the Trader Support Service, your business must hold a valid XI EORI number. The XI EORI identifies your business for Northern Ireland customs procedures. If you don’t have one, apply through HMRC before registering for TSS. See our XI EORI guide.
Yes. You need a GB EORI for standard UK customs declarations and an XI EORI for Northern Ireland-specific procedures. TSS registration requires the XI EORI. See our EORI guide.
TSS handles customs declarations for GB–NI movements. Your XI EORI identifies your business in Northern Ireland customs. UKIMS (UK Internal Market Scheme) is a separate registration that allows qualifying businesses to declare goods as “not at risk” of entering the EU single market, which can reduce customs requirements. All three may be relevant for businesses trading regularly with Northern Ireland.

Registering for tss

Register online through the official GOV. UK Trader Support Service portal at gov.uk/guidance/trader-support-service. The process is free and straightforward. You will need your XI EORI number, business details, and basic information about the goods you trade between Great Britain and Northern Ireland.
Registration is usually processed quickly — typically within a few working days. Once approved, you receive your TSS reference number and can begin submitting declarations immediately.
No. TSS registration must be completed by the business directly through GOV.UK. Pallet2Ship can guide you on when TSS is needed and direct you to the registration portal, but we cannot register on your behalf.

Using tss

Once registered, TSS submits customs declarations on your behalf for goods moving between Great Britain and Northern Ireland. You provide shipment details (goods description, value, commodity codes, EORI numbers), and TSS handles the declaration process with HMRC. This means you don’t need to submit customs entries yourself or use separate customs software for GB–NI movements.
TSS primarily handles declarations for goods moving from Great Britain into Northern Ireland. For movements from Northern Ireland to Great Britain, customs declarations are not normally required.
Your shipment may be delayed or rejected at customs. Declarations cannot be processed without valid TSS registration, and carriers may hold goods until proper documentation is in place.

Practical considerations

TSS itself does not change duty or VAT rates. It processes declarations based on the information you provide. Whether duties apply depends on the goods, their origin, and whether they are classified as “at risk” of entering the EU single market. Goods registered under UKIMS as “not at risk” may face reduced or no customs requirements.
TSS is designed for GB–NI movements. Movements from Northern Ireland to the Republic of Ireland follow EU customs rules and may require different documentation. Contact our team or HMRC for guidance on NI–Ireland movements.
Full guidance, registration, and support are available on GOV. UK at gov.uk/guidance/trader-support-service. The TSS portal also provides training materials and updates on Windsor Framework customs procedures.
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