DUINs Were Only a Stepping Stone

As the UK REACH regime continues to evolve, companies relying on Downstream User Import Notifications (DUINs) should proactively assess whether the DUIN is still an appropriate means of covering their supply chain under UK REACH and, if necessary, begin preparing for the transition to a full registration. While DUINs have served as a valuable transitional mechanism following Brexit, it is not a long-term compliance solution.  

Proactive planning, particularly through early inquiry submissions, will significantly reduce future regulatory burden and risk.

The Limits of DUINs – Are You Certain You're Compliant?

DUINs were implemented as a temporary measure, aimed at covering existing downstream users and distributors who were importing into Great Britain (GB) under an EU REACH registration prior to the end of the UK REACH implementation period (IP) thereby allowing GB importers to continue operations based on the existing EU REACH registrations.  

The DUIN therefore only covers GB importers that were supplied under an EU REACH registration in the two years prior to Brexit.

As the time since the end of the UK REACH implementation period increases, i.e., the gap between 31st January 2020 and the first transitional registration deadline, it is likely that supply chains have developed and evolved with new suppliers or new importers entering the supply chain. It is important that supply chain changes are interrogated regarding their UK REACH compliance.

Any companies importing a substance into GB for the first time after the end of the UK REACH IP or importing from a non-EU supplier who’s supply chain is not ‘protected’ by an existing EU REACH registration will not be covered under a DUIN. For these supply chains, companies with registration obligations must instead pursue registration under UK REACH.

This distinction is critical for businesses expanding their GB market presence or onboarding new customers, as failure to register appropriately could result in non-compliance. Before a registration dossier can be submitted, first, an inquiry dossier must be submitted and accepted.

Should You Initiate the Inquiry Process Now?

Blue Frog strongly recommend that companies begin the inquiry submission process for DUIN-listed substances that they intend to proceed towards UK REACH registration irrespective of tonnage band. This early step offers several strategic advantages:

1. Clarity on Substance Identity

The inquiry process helps confirm key technical parameters such as:

• Substance identity under UK REACH
• Composition and impurities backed by analytical data
• Applicable tonnage band

These elements form the foundation of a compliant registration dossier and can take time to validate. Laboratory capacity is also an important factor to consider for any companies who do not have this internal capability or suitable existing data to rely on.

2. Early Engagement with Co-Registrants

Submitting an inquiry enables contact with existing or potential registrants of the same substance. This facilitates:

• Data sharing discussions
• Discussions relating to lead registrant identity
• Potential consortium participation or contribution to the initial joint submission agreement

Early engagement often leads to better understanding of the costs and substance group agreements and will enable companies to make earlier and more informed decisions, in collaboration with other registrants of the same substances.  

3. Alignment with Confirmed UK REACH Deadlines

Following the UK REACH consultation, the UK Government has confirmed its intention to delay the existing registration deadlines. Under the updated UK REACH framework, the revised transitional registration deadlines have been set for 2029, 2030 and 2031. These changes remain subject to completion of the legislative process, including the necessary consent from the Scottish and Welsh Ministers, before they are formally enacted.

The revised legislation is expected to be brought forward in 2026 through the usual parliamentary process, with the aim of ensuring that the new deadlines and associated compliance arrangements are in place well ahead of the first extended deadline. In this context, beginning preparations now will help ensure that companies do not face an unnecessary rush and therefore additional cost as the new deadlines approach.

Having an inquiry in place will allow companies to make the most informed decisions in advance of the deadlines which maintains a relatively short route to full registration should circumstances in the supply chain demand registration before the deadlines.

4. No Fee for Inquiry Submission

The inquiry stage itself does not require a submission fee, making it a low-cost, high-value step toward compliance planning.

5. Reducing Future Regulatory Risk

DUIN is temporary by design. Transitioning toward full registration is inevitable, and delaying preparation may lead to:

• Compressed timelines
• Increased costs
• Supply chain disruption

Taking action now allows for a more controlled and strategic transition.

The Role of NRES in UK REACH

A registration is required when imports are not eligible to be covered by a DUIN, for example, when:  

• Companies are new UK importers of a substance post UK REACH IP.
• Supply chains have changed and fall outside the original DUIN scope  
• The substance was not registered in the EU prior to Brexit (i.e., a Novel Substance)

A New Registration of an Existing Substance (NRES) is a less data intensive, and therefore cheaper, route to registration for all substances which were registered in the EU prior to Brexit. Full data requirements will need to be met by the transitional deadlines and however DEFRA have now confirmed that the reduced data requirements will be in line with their proposed Alternative Transitional Registration model (ATRm) as confirmed in March 2026. Novel substances must be registered according to full REACH data requirements before manufacture/import at >1 tonne per annum.

It is also possible to proceed to NRES following inquiry even where an eligible DUIN is still in place. Proceeding through this process successfully means that a UK REACH registration number will be issued, and there are no restrictions upon the supply of the substance meaning companies can build a truly robust supply chain which will provide confidence and security for customers.  

How Can Blue Frog Support

Blue Frog are experts in EU & UK REACH. We can support you with:

• Portfolio assessment and compliance gap analysis
• Inquiry dossier preparation and submission
• NRES strategy and registration planning
• Potential Data sharing and consortium engagement

Initiating the inquiry process now is a practical and cost-effective way to prepare for full UK REACH compliance. It provides clarity on your regulatory obligations, supports business continuity, and positions your company for a smoother transition beyond DUIN.

If you would like us to proceed with an inquiry for your DUIN substances, or to discuss the implications of NRES, or the registration deadlines in more detail, please feel free to get in contact and speak directly with one of our UK REACH Consultants. We would be pleased to review your portfolio and provide tailored recommendations.