From 1 October, HMRC starts emailing the businesses registered for the Trader Support Service. That email is not a newsletter. It carries the pre-enrolment instructions for a replacement platform that goes live on 20 October, and HMRC has already warned that businesses which have not prepared "may not be able to move your goods" (GOV.UK, 2026). If you sell anything into Northern Ireland from Great Britain, this is a half-hour job sitting in an inbox you may not check.
TL;DR: The Trader Support Service moves to a new platform on 20 October 2026. Your account carries across, so there is no fresh registration, but you still have to complete a pre-enrolment step: new password, confirm your profile, check user permissions. HMRC starts sending invitation emails on 1 October. Budget 30 minutes.
What Is Changing on 20 October 2026?
The platform underneath the service, not the service itself. The Trader Support Service continues as a free government facility that files customs and safety and security declarations on your behalf for goods moving from Great Britain to Northern Ireland. From 20 October 2026 it runs on a new system operated by Netcompany and hosted on GOV.UK, replacing the Fujitsu-led platform that has run it since 2020 (GOV.UK, 2026).
Two things happen on that date. All new movements must be submitted on the new platform, and the existing one stops accepting them. Netcompany holds a five-year contract with two possible one-year extensions, so this is a long-term replacement rather than a stopgap. The new system has been in private beta since July 2026, with several hundred declarations already submitted through it.
Your customs obligations do not change. The Windsor Framework rules and the declaration data stay exactly as they are. Only the front door moves.
Do You Need to Register for TSS Again?
No. HMRC's guidance is explicit that existing users "will be migrated to the new service and will not need to register again". But migration and readiness are two different things, and this is where we expect most of the damage to be done.
The account comes across automatically. The pre-enrolment step does not. You have to open the invitation email, set a new password, and confirm that your profile details and user permissions are correct. HMRC puts that at five to 30 minutes depending on the size of the business and how quickly you can lay hands on the information.
What we see most often with changes like this is a reader who takes the reassuring half of the message and stops. "I have been migrated" is true. "So I need do nothing" is not. Read both GOV.UK pages together and the resolution is simple: no new registration, but yes, a short task to complete before the cutover.
Who This Affects, and Who It Doesn't
HMRC has contacted more than 66,000 registered businesses about the switch, with guidance, webinars and support material (GOV.UK, 2026). That is the population: anyone signed up to TSS to handle GB to Northern Ireland movements.
In practice that means smaller manufacturers, wholesalers and online sellers who ship to Northern Ireland customers and who joined TSS precisely because it does the declarations for them. The service has handled over two million consignments across more than 560,000 goods movements since the Northern Ireland Protocol took effect (Chartered Institute of Taxation, 2022), so the user base is broad and skews small.
If you do not move goods into Northern Ireland, nothing here applies to you. If a customs agent files for you through their own software rather than through TSS, this is their job and not yours.
What Happens If You Miss the Deadline?
You lose the ability to submit new movements through TSS until you complete pre-enrolment. The declarations themselves do not vanish, and HMRC has not said that movements already in flight are cancelled, but a shipment you cannot declare is a shipment that does not leave.
There is no penalty attached to missing pre-enrolment, because this is an administrative cutover rather than a filing deadline. The cost is operational: stock sitting in a yard while you wait in a support queue full of people who left it just as late. HMRC runs a TSS contact centre on 0800 870 8173, open 8am to 5:30pm, seven days a week.
Your fallback if you do get caught out is to appoint a customs agent or submit directly through the Customs Declaration Service using commercial software. Both work, and both cost money and lead time that pre-enrolling in October does not. We would treat them as recovery options, not as a plan.
Your Pre-Enrolment Checklist
One question clients always ask at this point is who in the business is actually going to receive the email. Start there, because the address on a TSS account registered in 2021 is often a shared inbox nobody reads or a staff member who has since left.
- Confirm which email address the TSS account uses, and that someone still monitors it.
- Watch for the HMRC invitation from 1 October and treat it as a real task, not an FYI.
- Complete pre-enrolment: new password, profile details, user permissions. Allow 30 minutes.
- Use the test environment HMRC provides to run a dry submission before the cutover.
- Check your UK Internal Market Scheme authorisation is still current while you are in there.
That last point is worth a minute of your time. UKIMS authorisation is what lets you declare goods "not at risk" of entering the EU, and the processing conditions turn on a £2 million annual turnover test, with carve-outs for food sold to UK consumers, construction, health and care, animal feed and non-profit activity (GOV.UK, 2026). Businesses that have grown since they first applied sometimes find the basis of their authorisation has moved underneath them.
Other UK rule changes also land this month, including wider right to work checks from 1 October and the temporary zero rate on business electricity. If you sell online, the marketplace VAT threshold proposals are worth reading alongside this one.
Frequently Asked Questions
Do I have to pay for the new Trader Support Service platform?
No. TSS remains free to use. The platform is funded by HMRC under its contract with Netcompany, and there is no subscription or per-declaration charge to traders.
What if I never receive the invitation email?
Call the TSS contact centre on 0800 870 8173. The most common cause is a stale email address on the account, which the contact centre can help you correct. Do not wait until mid-October to chase it.
Does 20 October affect declarations I have already submitted?
HMRC says the date applies to new movements. It has not said that movements already submitted are cancelled or need resubmitting, and you should not assume they are. If you have an open movement spanning the cutover, raise it with the contact centre rather than guessing.
Is this the same thing as the Trader Support Service closing down?
No. TSS was separately extended rather than ended. The service continues under a new provider and on new technology. Any coverage describing it as withdrawn is wrong.
I use a freight forwarder. Do I still need to do anything?
Only if the declarations are filed through your own TSS account. If your forwarder uses their own customs software, the switch is theirs to manage. Ask them in writing which system submits your declarations, because "we handle customs" covers both arrangements.
If you move goods into Northern Ireland and you are not sure whether your TSS account, your UKIMS authorisation or your agent arrangements are in the right shape before 20 October, get in touch. We will go through your setup with you and tell you plainly what needs doing, and what does not. Our business services team works with UK companies on cross-border compliance across both our Manchester and Dubai offices.