UK REACH: Information for New Registrants
UK REACH Registration of new substances
For registrants [MS1.1]of a new chemical substance (i.e. not previously registered in the EU), there are no transitional provisions: a complete registration must be submitted before manufacture or import into Great Britain at or above 1 tonne per year can start. This applies to:
• GB based manufacturers or importers of chemical substances into GB
• GB legal entities that had submitted a dossier to ECHA but did not receive an EU registration number before EU exit.
• Only Representatives, i.e. GB legal entities appointed by non-GB companies to take on registration duties under UK legislation.
Existing substances – NRES
For GB-based manufacturers or importers of a chemical substance that was previously registered under EU REACH before Jan 2021, registrants may benefit from a simplified registration process before gaining market access, known as a New Registration of an Existing Substance (NRES). NRES allows substances that have previously been registered (by any EU legal entity) under EU REACH to be placed in the GB-market while deferring submission of the full registration requirements by the appropriate transitional deadline.
Deadlines and obligations
Under UK REACH, registrants benefiting from transitional arrangements must submit the rest of their registration dossiers by phased deadlines. The latest dates for submission of the remaining registration requirements are dependent on the annual tonnage of import/manufacture and the hazard profile of the substance. As of April 2026, transitional registration deadlines for UK REACH are as follows:
| Deadline (last date for dossier submission*) | Tonnage | Hazardous property |
|---|---|---|
| 27 October 2026 | 1000 tonnes or more per year | • Carcinogenic, mutagenic or toxic for reproduction (CMRs) - 1 tonne or more per year • Very toxic to aquatic organisms (acute or chronic) - 100 tonnes or more per year Candidate list substances (as of 31 December 2023) |
| 27 October 2028 | 100 tonnes or more per year | Candidate list substances (as of 27 October 2026) |
| 27 October 2030 | 1 tonne or more per year | N/A |
Defra have confirmed extension of these deadlines to 2029 (1000+ tonnes /year), 2030 (100+ tonnes /year) and 2031 (10+ tonnes / year), stating that the additional time will ensure that data becomes available “in a timely and orderly way”, whilst reducing the burden to SMEs and downstream users. As of April 2026, legislation has not yet been updated.
Registrants benefiting from the deferred deadlines must plan to assemble and submit the full registration requirements in a timely manner by their substance’s respective deadline, while still ensuring they have sufficient hazard and use information to manage risks.
Failure to meet these transitional deadlines risks loss of market access for the affected substance in GB and potential enforcement action.
These deferred deadlines are not applicable to new registrations of new substances (which are not or were not registered in the EU prior to Jan 2021). Therefore, new registrants are expected to submit a complete registration dossier before being able to place their substance in the GB market are 1 tonne per year or more.
Whether you are looking to understand if you can benefit from these transitional agreements, or need support preparing a registration dossier for your substance, feel free to reach out to the Chemicals Team at RPA with your query: post@rpaltd.co.uk