Do I need to appoint a lead assessor for my ESOS audits, or can I do everything in house?

You will need to appoint a qualified lead assessor to check that your assessment meets ESOS requirements (unless 100% of your energy use is covered by ISO 50001 certification).

Your lead assessor can either:

  • carry out your ESOS assessment and audits themselves
  • check that the assessment and audits done by people who aren’t lead assessors meet the requirements.

Your lead assessor must be a member of an approved ESOS lead assessor register. You can find the list of approved registers on the gov.uk website.