If you move goods between Great Britain and Northern Ireland, the Trader Support Service is changing this month, and the change is already live in practice even though the official date is two weeks away.

The service moves to a new platform on 20 October 2026. From that date, all new movements have to be submitted on the new service. The current platform stops taking them.

That reads like a date to diarise and deal with nearer the time. It is not, because of how pre-lodgement works.

What the Trader Support Service actually is

For anyone coming to this without the background, the Trader Support Service (TSS) is a UK government service for businesses moving goods between Great Britain and Northern Ireland. It can complete customs and safety and security declarations on your behalf, and it offers education, training and advice on how goods move under the Windsor Framework.

It is free to use. That is worth saying plainly, because it is not a product anyone is selling you. You can use it if you are moving the goods yourself, or if you act for someone else, as a haulier does.

The 20 October change, and why it starts now

The headline is simple. The new service goes live to all users on 20 October 2026, and from that date all new movements must be submitted on it.

The part that matters more is the timing of the declarations themselves. Declarations can be pre-lodged up to 14 days before the goods arrive, and the current platform will not accept pre-lodged declarations for goods due to arrive on or after 20 October.

Count back 14 days from 20 October and you land on 6 October. So from now on, any declaration you would normally prepare in advance for a load arriving on or after 20 October cannot go through the current platform. It has to go on the new service.

The first sign for most businesses will not be a headline. It will be a declaration that will not go through for a load booked for later in the month.

What to do about it

Pre-enrol for the new service now. Existing users are being migrated and do not need to register again, but they do need to pre-enrol. HMRC started sending invitation emails to current users on 1 October. Pre-enrolment means setting a new password and updating your business details and permissions, which HMRC says takes between 5 and 30 minutes depending on the size of the business. It also gives you access to a test environment so you can get used to the platform before you rely on it. If you have not seen the email, check junk folders and whoever else in the business might receive it.

If someone else files your declarations, ask them this week whether they are set up on the new service and how they are handling loads arriving on or after 20 October. It is a short question, and an agent who has not heard of the change is something you want to find out now rather than with a lorry waiting.

If a specific load sits awkwardly across the changeover, ask the Trader Support Service directly. Advice is part of what it provides, and it costs nothing to check.

Why this lands harder in Northern Ireland

This is not a UK-wide administrative change that happens to reach here. It only exists here.

A business in Manchester moving goods to Leeds files nothing. The same business moving the same goods to Belfast is dealing with customs declarations. That difference is the reason the Trader Support Service exists, and it is why the businesses affected are almost all Northern Ireland ones: hauliers, freight forwarders, retailers bringing stock across, manufacturers bringing in components, and food and agriculture businesses moving product. If your loads move between Great Britain and Northern Ireland, this is part of your week whether you think about it or not.

If you are in the transport side of this, our page for logistics and haulage businesses covers the wider accounts and VAT picture, and our guide to VAT for NI retailers under the Windsor Framework covers the VAT side for businesses bringing stock across.

Where Arro Group comes in

We help clients with the Trader Support Service: registration and account setup, customs declarations for goods moving from Great Britain to Northern Ireland, and getting set up on the new service before 20 October. It is available to new clients as well as existing ones, and we price it case by case.

If you move goods to or from Great Britain and you are not certain where you stand for the rest of October, the useful thing is a short conversation. What we would want to know is what you move, who files your declarations now, whether you have pre-enrolled, and whether you have anything arriving on or after 20 October. That is usually enough to tell you whether you have a problem. If it turns out you are fine, we will tell you that.

You can read more about our Trader Support Service help, contact us or call 028 9508 4138.