UK REACH is Great Britain's post-Brexit chemicals regime, requiring manufacturers and importers of substances at one tonne or more per year to register with the HSE, whcich acts as the Agency for the GB market.
Businesses that previously relied on EU REACH registrations must complete transitional registrations under the UK framework, and those deadlines have just moved.
The New Deadlines
In March 2026, the Government laid draft legislation before Parliament that pushes back all three transitional registration deadlines by three years, one year and one year, respectively.
The deadlines are phased so the most hazardous and highest-volume chemicals are registered first:
- 27 October 2029: substances made or imported at 1,000 tonnes or more a year, plus the most hazardous substances: those on the candidate list, substances that can cause cancer, genetic damage or harm to reproduction (at 1 tonne or more), and substances very toxic to aquatic life (at 100 tonnes or more). Previously due October 2026.
- 27 October 2030: substances at 100 tonnes or more a year, and anything added to the GB candidate list from January 2024 onwards. Previously due October 2028.
- 27 October 2031: everything else at 1 tonne or more a year. Previously due October 2030.
HSE's deadlines for checking submitted dossiers move back in step, so evaluation will follow the new submission dates rather than the original calendar.
Why the extension? The ATRm is finally taking shape
When the UK left the EU, registration data held by the European Chemicals Agency (ECHA) did not transfer to the HSE. Businesses faced rebuilding hazard data packages from scratch at an estimated industry cost of up to £2 billion. The Alternative Transitional Registration Model (ATRm), first consulted on in 2024, is the Government's answer, and its final approach was published on 30 March 2026.
The headline: transitional registrants will submit significantly less upfront data than EU REACH originally required, with the Government estimating a reduction of around 70% in one-off registration costs. The model works by treating regulatory decisions from trusted jurisdictions, principally the EU, as the starting point, rather than duplicating assessments already completed.
Three principles remain intact:
- "No data, no market" still applies. Registration remains mandatory for substances placed on the GB market at ≥1 tonne per year.
- HSE retains call-in powers. Where risk justifies it, the regulator can request additional information after registration.
- Duty of care is unchanged. SDS, GB CLP and COSHH obligations continue throughout the transitional period; the extension does not pause chemical risk management.
What should duty holders do for now?
The extension is breathing room, not a reprieve. Between now and October 2029, importers and manufacturers should:
- Confirm your substance portfolio and tonnage bands. Which deadline tier does each substance fall into? Candidate list additions between 2024 and 2026 sit in the second tier; check the GB list, not ECHA's.
- Verify your DUIN notifications. Downstream User Import Notifications secured your transitional status; registration still has to follow.
- Review Only Representative arrangements. GB entities relying on EU suppliers should confirm who carries the registration duty.
- Don't assume EU dossiers transfer automatically. The ATRm uses EU decisions as a starting point, not a rubber stamp. HSE retains discretion to diverge.
- Monitor the secondary legislation. The final ATRm statutory instrument will define the exact data requirements. Build it into your legal register review cycle now.
How can iCOR support organisations with UK REACH's legal obligations?
iCOR helps organisations to reduce reliance on spreadsheets, save time, and feel more confident about legal and operational risk and compliance. The platform includes a self-audit tool that maps applicable environmental, health, and safety legislation into a tailored legal register, and allows you to track compliance actions, assign responsibilities, and present your progress. iCOR's legal register tracks UK REACH developments as they happen, flagging exactly which duties apply to your operations
Book a demo here to learn how iCOR can help you with UK REACH's legal obligations, turning compliance into an integrated and continuous process that is accessible to everyone.
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