There are rumours circulating about making ESOS an annual affair from 2019 which would be a significant step forward in the reduction of corporate energy use but, in the meantime, here’s a simplified view on the 3 key dates you need to be aware of for ESOS Phase 2.

1 – The Reporting Date – 5th December 2019

This is the deadline by which your ESOS report must be completed, signed off and filed with the Environment Agency.

2 – The Qualification Date – 31st December 2018

This is the magic decision date – if you’re “in” on this date, you have to do ESOS Phase 2 and conversely, if you’re “out” then you don’t.

This is also the date at which you must operate assets for them to qualify for ESOS.  If you don’t operate them on this date and still operate them on the 5th December 2019 you can exclude them from ESOS.  “Assets” in relation to ESOS normally refers to buildings or vehicles.

  • This means a building you are in now but you aim to leave before 31st December 2018 is EXCLUDED from ESOS.
  • This also means that if you are moving into a building but you wont have moved in before 31st December 2018 it is EXCLUDED from ESOS.
  • And finally, the good news for the gentleman I spoke to last week who had a brand new Aston Martin as a company car but is probably getting rid of it before 31st December 2018 is that it will also be excluded from ESOS.

3 – The Data Collection Period: any 12-month Period containing the 31st December 2018

This is the data collection period.  We analyse your electricity, gas, transport etc. bills for this period and use this analysis in our ESOS report for you.  I normally use calendar year 2018 for this period.


ESOS Tip1: Don’t leave it until the last minute

You must analyse your energy use for a 12-month period which contains the 31st December 2018.

In theory, you could put all of your energy bills and transport information into a cardboard box and give them all to an ESOS Lead Assessor on the 4th December 2019 and everything could be done on time, but I hope you can see the risks and disadvantages associated with this (see the diagram above).  In the same way my accountant could, in theory, take a year’s worth of bills and payments on the last day before the accounts are due and produce a decent set of accounts in 24 hours, in practice this is an idiotic idea.

Research carried out by the government also indicates that if you leave it late to get started:

  • You are likely to pay more for your ESOS report
  • You are likely to be less satisfied with your ESOS report


ESOS Tip2: Process the data monthly as you go along

I encourage all my clients to send us their energy and transport data to our data processing team monthly at the end of each month during 2018.  This way, if there are gaps, omissions or incorrect invoices we can spot them and sort them out there and then.  In my experience, correcting an error in the data from the previous month is so much easier than correcting something from the previous year.


ESOS Tip3: What happens if you’re late?

We need to split this question into two different circumstances:

What happens if you file late and have all the data you need?

There are no precedents concerning how the Environment will react but, in theory at least, there’s a £5,000 fine to pay rising by £500 per day.  In practice, however, for ESOS Phase 1 they issued sternly worded threats but actually issued very few fines and I’ve heard on the grapevine that they only issued those fines to people who didn’t do ESOS at all rather than were just late filing.

What happens if you file late and realise when you come to file that some of the required data was not collected?

This is a different situation altogether and a potentially expensive one.  Whilst, again, there is not any precedent to go on, I am led to believe by the Environment Agency that fines might well be issued in these circumstances.  This amplifies the benefit of acting sooner rather than later as we can check your data as we go along and if there are any gaps we can address them whilst there is still time.



Much of the way you choose to interpret the dates for ESOS will come down to your attitude towards risk.  You must file before 5th December 2019 but:

  • Those that are risk/cost adverse will have started their ESOS data reporting by now and there will not be any nasty surprises in 2019 when the reports are collated, checked and filed.
  • Conversely, those that have a more relaxed view towards corporate risk will start the process late and leave it to the last minute to file their report.

From experience, the former is by far the preferred route but I appreciate you are (in theory at least) busy and for some ESOS is nothing but an unwanted distraction.  My plea to those in this category, therefore, is to reserve a small block of time at the end of each month in 2018 to collect the required data and send it through to me ASAP.  It may be a small inconvenience now, but it saves a mad panic (and potential fines) in 2019.

As usual, if you have any questions, please just get in contact, my details are below.


Want more information?  Download our “Top 5 Tips On How to Make The Most Out Of ESOS”

Enistic help companies manage their energy and have been doing so since 2009.  We are market leaders in ESOS auditing, energy monitoring via meters of all forms and we carried out over 2,000 ESOS site audits during ESOS phase 1.  We develop and maintain Plato, a cloud-based Energy Management Platform that helps a large number of medium-sized and Enterprise level organisations manage their energy in real-time throughout the world, including several listed companies.  We are based in Oxford but have distributors worldwide and have national reach when it comes to ESOS Audits.

If you would like more information about ESOS and see our Top 5 Tips On How to Make The Most Out Of ESOS, click here to download our guide.

Want some help?  Speak to Darryl Mattocks

Darryl is the founder of Enistic and has personally been the responsible ESOS Lead Assessor on over 150 ESOS Audits.  He advises on how to reduce energy use in over 2,000 sites throughout the UK and is doubly certified for ESOS by two independent ESOS approval bodies.   He is an approved ISO50001 Lead Auditor and holds the industry-specific CEM and CMVP qualifications awarded by the Association of Energy Engineers.

He is happy to answer any ESOS or energy management related questions you may have and can be contacted by email at or by phone on 01865 598 776.