Preparing for ESOS Phase 4: Key Actions and Deadlines for Compliance

Written by: Energy Guardians

Last Updated: April 26, 2025.

With the Energy Savings Opportunity Scheme (ESOS) Phase 4 now underway, UK businesses must begin preparing to meet the upcoming compliance requirements. The next phase brings a continued focus on energy efficiency, enhanced data reporting, and alignment with long-term sustainability goals, including the potential integration of net-zero principles.

Critical Deadlines to Note:

• Phase 4 Compliance Period: December 6, 2023 – December 5, 2027

• Qualification Date: December 31, 2026

• Compliance Deadline: December 5, 2027

• Phase 3 Action Plan Submission Deadline: March 5, 2025

Key Steps to Prepare for ESOS Phase 4:

1. Review Phase 3 Action Plans

Re-assess your Phase 3 energy efficiency strategies to ensure alignment with the evolving ESOS framework and best practices. Use these insights to inform your Phase 4 activities.

2. Initiate Robust Data Collection and Monitoring

Begin tracking energy usage from the start of the compliance period (December 6, 2023). High-quality, consistent data collection is essential for accurate and timely reporting.

3. Explore Net Zero Opportunities

Although net-zero requirements have been deferred to Phase 5, organizations are encouraged to voluntarily integrate net-zero assessments into their Phase 4 strategies. The upcoming PAS 51215-1:2025 and PAS 51215-2:2025 standards can provide valuable guidance.

4. Prepare for Reporting Process Enhancements

Anticipate changes to the MESOS reporting portal. Stay informed and ensure your teams are trained on any new system functionalities to streamline the submission process.

5. Ensure Qualification and Compliance Readiness

Confirm that your organization meets the ESOS qualification criteria and is on track to compile and submit all required documentation before the December 2027 deadline.

6. Stay Informed with Regulatory Updates

Monitor updates and guidance from the Department for Energy Security and Net Zero (DESNZ) to remain compliant with evolving regulatory requirements.

7. Start Early to Minimize Risk

Early planning and proactive implementation can help distribute costs, minimize compliance risks, and build a strong foundation for long-term energy efficiency improvements.

Conclusion

The transition to ESOS Phase 4 presents an opportunity for businesses to enhance their energy management practices and prepare for a future aligned with sustainability goals. Early engagement and ongoing attention to regulatory developments will be key to a smooth and successful compliance journey.

If your organization needs guidance or hands-on support navigating the complexities of ESOS Phase 4, Energy Guardians is here to help. Our team of experts provides tailored solutions to ensure compliance, improve energy performance, and future-proof your business.

Get in touch with Energy Guardians today to discuss how we can support your ESOS strategy and help you make the most of this important regulatory milestone