Since 1 June 2026 the UK has run the final NCTS Phase 6: transit declarations in GB/XI may only use security types 0 and 2, and ENS data is lodged separately. Here is what changed and what to verify in your T1 declarations.
Contents
- Where does NCTS Phase 6 come from?
- Stage 1: 1 September 2025 — what changed
- NCTS Phase 5 final state — in force since 21 January 2025
- Stage 2: 1 June 2026 — the key changes for T1 declarations
- What you need to do — a checklist
- UK vs EU — different approaches to NCTS6
- How we help
- Sources
- Need a T1 transit document under NCTS Phase 6?
Companies importing and exporting goods through the United Kingdom under T1 transit are now working with a changed NCTS system. After the rollout of Phase 5 and its final state in January 2025, the UK moved to NCTS Phase 6 — in two stages (1 September 2025 and 1 June 2026). This article explains what applies, what came into force on 1 June 2026, and what to check in how transit declarations are handled.
Where does NCTS Phase 6 come from?
NCTS (New Computerised Transit System) is the electronic system for handling customs transit under the Common Transit Convention (CTC). The EU has run NCTS for years, and each successive "phase" is a system upgrade — new messages, expanded data, integrations with other systems.
NCTS Phase 5 went live in the UK in 2024. Phase 5's final state rules, with the full set of new features, came into force on 21 January 2025 in all CTC countries.
NCTS Phase 6 is the next generation — it allows countries that use it (opt-in) to carry safety and security (ENS) data in the transit declaration – in Transit/Security Accompanying Documents (TSADs) – and links NCTS with ICS2 Release 3. Countries that do not use this integration (opt-out), such as the UK, accept transit declarations without ENS data. The European Commission (DG TAXUD) asked administrations to implement NCTS6 by 1 September 2025 or as soon as possible thereafter — HMRC delivered it in two stages. For carriers, see ICS2 and NCTS-P6 in 2026.
Stage 1: 1 September 2025 — what changed
On 1 September 2025, HMRC rolled out the first stage of NCTS Phase 6 (Phase 1). This was an interim release — an update to the NCTS5 system with bug fixes, serving as a bridge to full Phase 6, not the final NCTS6.
For day-to-day users there were few functional changes — the key procedural changes only come with stage 2.
NCTS Phase 5 final state — in force since 21 January 2025
Before we get to Phase 6, it's worth recapping what came into force under Phase 5's final state. These elements still apply and form the basis for the further changes:
| Change | Status from 21.01.2025 |
|---|---|
| Commodity codes | 6-digit HS code mandatory for every goods item |
| Paper TAD (Transit Accompanying Document) | No longer mandatory — the electronic MRN is sufficient |
| Multiple house consignments | Available (not via the government portal) |
| Pre-lodged declarations | Available — can be submitted and amended in advance |
| Office of Incident | New feature for reporting incidents |
Commodity codes are the one point that still trips up smaller companies. Since 21 January 2025, every goods item on a transit declaration must have a 6-digit HS code that matches the goods and their description (XI declarations may optionally add 2 CN digits).
Stage 2: 1 June 2026 — the key changes for T1 declarations
Stage 2 — the final NCTS6 — came into force on 1 June 2026. This is the change that directly affects the day-to-day work of customs agents and transport operators. Below are the key changes announced by HMRC — for current notices, see HMRC's transit newsletters.
Change to security codes (Security Types)
Under NCTS5, four codes were available in the Security field (safety and security data — not to be confused with the customs guarantee): 0–3. From 1 June 2026, only the following are available:
| Type | Description | Available after 1.06.2026 |
|---|---|---|
| 0 | No safety and security data (No security) | YES |
| 1 | ENS (Entry Summary Declaration) | NO — rejected |
| 2 | EXS (Exit Summary Declaration) — exit declaration data only | YES |
| 3 | ENS + EXS (combined) | NO — rejected |
Using type 1 or 3 after this date will cause the NCTS system to automatically reject the declaration and delay the movement of goods. If you use third-party software — confirm with your provider that the software only allows codes 0 and 2.
Incidents during transit
Since the final state of Phase 5 (21 January 2025), an incident during the journey – for example a change of vehicle or damage to seals – must be reported immediately to the nearest office of incident, with the MRN; you can no longer wait until arrival at the destination (HMRC newsletter, January 2025).
For the last step of a movement, see how to close a T1 in Poland.
UK opt-out from TSAD/ICS2 integration
HMRC has decided that the United Kingdom does not use TSADs or NCTS6 integration with the EU's ICS2 system (the opt-out model). This means:
- Since 1 June 2026 a transit declaration in NCTS GB/XI may not contain ENS data (HMRC rejects security types 1 and 3) — the ENS is lodged separately: for the UK as a Safety and Security GB declaration to HMRC, and on entry into the EU in ICS2; there is no single combined declaration
- Source: HMRC – NCTS Technical Interface Specification, UK specific rules
- The UK stays with its own GVMS (Goods Vehicle Movement Service) system for movements requiring a GMR
What you need to do — a checklist
If you handle T1 transit through the UK, check the following (rules in force since 1 June 2026):
- Customs software — has your provider published an update supporting only Security Types 0 and 2? If not — contact your provider urgently.
- Declaration templates — review your saved declaration templates and remove Security Types 1 and 3.
- Incident procedures — make sure your internal SOPs require road incidents during transit to be reported immediately to the nearest office of incident.
- Commodity codes — make sure every item has a 6-digit HS code (mandatory since 21.01.2025).
- Team training — let your staff and subcontractors know about the changes to security codes (Security).
UK vs EU — different approaches to NCTS6
Common Transit Convention countries are rolling out NCTS Phase 6 on different dates and in different variants. Some use the ICS2 integration (opt-in) and allow ENS data in the transit declaration, while others – like the UK – use NCTS6 without it (opt-out). For UK–EU movements this means two separate obligations: the transit declaration in NCTS and the ENS – to the UK as Safety and Security GB, or to the EU via ICS2. Check the current position on the Polish side on the PUESC portal (puesc.gov.pl).
How we help
The agencjacelna.uk customs agency handles T1 transit declarations for imports from the UK to Poland and exports from Poland to the UK. We follow HMRC notices on NCTS changes. If you have any doubts about the correctness of your T1 declarations after the Phase 6 changes — get in touch with us before shipping.
Sources
- New Computerised Transit System (NCTS) 6 — GOV.UK
- January 2025 — NCTS Phase 5: final state rules — GOV.UK
- CTC Traders API roadmap — HMRC Developer Hub
Need a T1 transit document under NCTS Phase 6?
We prepare T1/T2 transit declarations in line with the new NCTS Phase 6 system.
Call: +44 333 335 5072 or go to our contact form. An individual quote is provided once you've sent your documents.
A customs agency registered with CDS, UK EORI number.
Frequently asked questions
Is a paper TAD still required?
No. Since 21 January 2025 the paper TAD is no longer mandatory – the driver does not have to carry it. The goods are presented with the MRN, which can be shown electronically (HMRC).
What happens if I lodge a declaration with security type 1 or 3 after 1 June 2026?
From 1 June 2026 HMRC applies a validation that rejects IE015 and IE013 transit declarations with security type 1 (ENS) or 3 (ENS + EXS). The declaration must be corrected and lodged again, so the movement of the goods may be delayed.
Does a transit declaration from the UK contain ENS data?
No. In NCTS GB/XI, since 1 June 2026 only types 0 (no safety and security data) and 2 (EXS exit data) are allowed. The ENS for the UK is lodged as Safety and Security GB with HMRC, and on entry into the EU in ICS2.
Does NCTS Phase 6 change the T1 procedure between Poland and the UK?
Indirectly, yes. A single T1 operation can run from an office of departure in GB to an office of destination in Poland, but the ENS for entry into the EU has to be lodged separately in ICS2 because the UK uses the opt-out model. The transit itself is ended at the office of destination or with an authorised consignee.
How do I report an incident during transit?
Since the final state of Phase 5 (21 January 2025) an incident, such as a change of vehicle or damaged seals, must be reported immediately to the nearest office of incident rather than on arrival at the destination.
Where can I check whether NCTS GB is available?
On the HMRC page NCTS availability and issues on GOV.UK (gov.uk/guidance/new-computerised-transit-system-service-availability).
Related guides
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