For any business moving goods between Great Britain and Northern Ireland, the Trader Support Service is the quiet workhorse of the Windsor Framework: a free, government-backed service that can complete the customs and safety-and-security declarations those movements need. And it is about to change platform - every user moves to a new service on 20 October 2026.
The Trader Support Service exists to help businesses adapt to the changed way goods move in and out of Northern Ireland. It is free to use and does two things. First, it offers education, training and advice about how goods move under the Windsor Framework. Second - the part that matters operationally - it can complete customs and safety and security declarations on a business’s behalf where those are required for movements between Great Britain (England, Scotland and Wales) and Northern Ireland, so the business does not have to work inside HMRC’s systems directly.
Both sides of the movement can use it: the business moving its own goods, and a haulier acting on behalf of someone else. That second case is the freight industry’s bread and butter - a carrier moving a customer’s consignment can lean on the TSS to get the declarations done rather than building in-house customs capability for the NI leg. HMRC has chosen the Trader Support Service to provide this service, which makes it the supported route rather than a commercial intermediary.
The next phase of the Trader Support Service goes live to all users on 20 October 2026; it is currently in private beta. Two facts matter for anyone already signed up. Existing users of the outgoing service will be migrated to the new service and will not need to register again. And from 20 October 2026, all new movements must be submitted using the new service - the old one stops taking submissions.
Further guidance on accessing the new service is promised shortly, and a new contact centre is already running: 0800 870 8173, open 8am to 5.30pm, seven days a week.
For planning purposes, the weeks either side of 20 October deserve the same treatment as any systems cutover: confirm the migration has happened, verify logins work on the new service before a live movement depends on them, and make sure the traffic office knows which platform a declaration went through if a query arrives.
The honest answer is anyone touching GB-NI movements who has not already prepared for the Windsor Framework changes - the government’s own warning is that unprepared businesses may not be able to move their goods at all. Registration runs through the Trader Support Service website. Even businesses that use a customs agent for the declarations benefit from the education side, because the agent will assume the trader understands the framework’s basic categories: what counts as a movement at risk, what data a declaration needs, who holds the EORI.
Carriers sit in an exposed spot on NI routes: the declaration obligation typically belongs to the trader, but the truck, the ferry slot and the driver’s day belong to the carrier. A missing or late declaration shows up as a held vehicle, whatever the paperwork says about responsibilities. Using the TSS - directly, or confirming the customer is using it - is the cheapest insurance on the route. Free, endorsed, and from 20 October 2026 on new rails: three good reasons to check the setup now rather than at the port.
The education side of the TSS is worth more than it sounds. The Windsor Framework’s categories - which movements need declarations, what data each declaration requires, whose EORI goes on the entry - are not intuitive, and the businesses that struggle on NI routes are usually struggling with concepts rather than forms. The TSS’s training exists precisely to close that gap, and it costs nothing.
For hauliers acting on customers’ behalf, the division of labour is worth writing down before the first consignment: who signs up to the TSS, who supplies the goods data, who confirms each declaration has been completed before the vehicle is released to the port. The service can complete the declarations, but it cannot conjure the commercial data - the invoice detail, the commodity description, the parties - that every entry is built from. The smoothest NI operations treat that data handover as part of the booking, not an afterthought at the dock. None of this costs anything but attention. The service is free, the migration is automatic for existing users, and the only real deadline behaviour required is a working login on the new platform before the first post-20-October movement depends on it.