How to Book an ECO4 Survey

How to Book an ECO4 Survey: Step by Step in 2026

Booking an ECO4 survey does not go through a government office or a single national booking system. You book directly with a TrustMark-registered installer, and which installer you contact depends on whether you are applying through your energy supplier's obligation route or your council's LA Flex route. Understanding this distinction before you start searching saves time and avoids ending up on the wrong list entirely.

Important: InstantGrant is an independent grant information and application-support service. We are not the UK government, Ofgem, TrustMark, or any installer. We do not book surveys ourselves. All guidance on this page is verified against Ofgem and TrustMark directory guidance as of 12 September 2026. Never pay any amount upfront to book an ECO4 survey.

This guide covers exactly where to find a legitimate installer to book with, what to check before confirming an appointment, how long the wait typically is, what happens if you booked through the wrong route, and the specific warning signs that a "survey booking" call is actually a scam.

Where to Find an Installer to Book With

Through Your Energy Supplier

If you qualify for ECO4 through a means-tested benefit, your own energy supplier is the most direct starting point. Most suppliers publish a "find an installer" tool or a downloadable list of approved contractors on their ECO4 page, filtered by postcode, and contacting one of these listed installers directly is how you book your survey under this route.

Through Your Local Council (LA Flex)

If you are applying through LA Flex because you do not receive a qualifying benefit, contact your local council's energy advice team first rather than an installer directly. Many councils maintain their own list of ECO4 contractors they work with under their Flexible Eligibility Statement of Intent, and booking through the council's recommended list keeps your application aligned with their specific Flex criteria.

Through TrustMark or Ofgem's Directory

Regardless of route, TrustMark's searchable directory of registered businesses lets you find PAS 2035-accredited retrofit installers by postcode directly, and Ofgem also maintains installer directory guidance you can cross-reference. Using these directories is particularly useful if your supplier's own list feels limited, or if you want to compare a wider set of options before booking.

What to Check Before You Confirm a Booking

Before agreeing to any survey date, verify the installer holds current TrustMark registration and PAS 2030 or PAS 2035 certification, since these are non-negotiable requirements for legitimate ECO4 work. For renewable technologies such as heat pumps or solar panels, also check for MCS certification, and for any measure involving a gas boiler, confirm Gas Safe registration specifically. You can verify all of these independently through the TrustMark website and the MCS installer database rather than relying solely on what the installer tells you over the phone.

Get More Than One Quote

Even though the survey itself is free, getting quotes and initial assessments from two or three different installers before committing to one is worth the extra time, since installers can vary in which measures they propose and how quickly they can schedule the actual installation work afterward. Booking your survey does not commit you to using that installer for the installation itself if you decide to compare options first.

How Long the Wait Typically Is

Once you contact a TrustMark-registered installer to book, initial contact and survey scheduling commonly happens within a few days to a couple of weeks, though this varies by region and by how much installer capacity remains as the scheme approaches its 31 December 2026 closure date. Popular measures and busy postcodes can see longer waits, particularly later in the scheme year, so booking sooner rather than later gives you a better chance of completing the full process, survey, approval, and installation, before the scheme closes.

What Happens After You Book

Once your survey is booked and completed, the installer submits their findings and a proposed specification to your energy supplier for funding approval, and if approved, they will outline an installation schedule with you separately from the initial survey appointment. Booking the survey is only the first of several steps, not the final commitment to specific work being carried out immediately.

Warning Signs When "Booking" a Survey

The pattern that most consistently indicates a scam rather than a genuine booking involves an unsolicited caller claiming to be from your energy supplier or a government scheme, offering to book a same-day or next-day survey without first confirming your specific eligibility route. Genuine bookings, whether through your supplier, council, or an installer you found independently, always involve confirming eligibility and identifying your qualifying benefit or Flex criteria before scheduling anything, and never require any payment or bank details simply to arrange the appointment.

If You Already Booked Through an Unverified Caller

If you have already agreed to a survey booking from an unsolicited call and are now unsure whether the installer is legitimate, verify their TrustMark and PAS certification independently before the appointment takes place, and cancel if you cannot confirm it. A completed but questionable ECO4 assessment on your record can sometimes prevent you from applying again through a more reliable route for the same measure, so verifying before the appointment matters more than cancelling afterward.

Common Misconceptions

"I book my ECO4 survey through GOV.UK or Ofgem directly." Neither GOV.UK nor Ofgem books surveys directly. You book with a TrustMark-registered installer, found through your supplier, council, or the TrustMark and Ofgem directories.

"Any company that mentions ECO4 must be legitimate to book with." Mentioning ECO4 by name does not confirm legitimacy. Always verify TrustMark, PAS 2035, and where relevant MCS or Gas Safe certification independently before confirming a booking.

"Booking a survey means I'm committed to that installer's work." Not necessarily. The survey and initial assessment are free, and you can compare quotes from more than one installer before deciding who carries out the actual installation.

Frequently Asked Questions

How do I book an ECO4 survey? Contact a TrustMark-registered, PAS 2035-certified installer, found through your energy supplier's approved list, your council's Flex contractor list, or the TrustMark and Ofgem directories, and arrange a free assessment directly with them.

Is there a government website to book an ECO4 survey through? No. There is no single government booking system. TrustMark and Ofgem provide installer directories, but the actual booking happens directly with the installer you choose.

How long will I wait for an ECO4 survey after booking? Typically a few days to a couple of weeks, though this varies by region and installer capacity, particularly as the scheme approaches its 31 December 2026 closure.

Do I have to pay to book an ECO4 survey? No. The survey is free for eligible households. Any request for payment to book or attend a survey is a clear warning sign of a scam.

What if I already booked through a cold caller and I'm not sure they're legitimate? Verify the installer's TrustMark and PAS certification independently before the appointment takes place, and cancel if you cannot confirm it.

How InstantGrant Can Help

Working out which route to book your survey through, your supplier or your council, and verifying an installer before you commit to a date can be confusing if you have never gone through the process before. InstantGrant is an independent grant information and application-support service that can help you understand which route fits your situation before you book anything.

We are not the UK government, Ofgem, TrustMark, or any installer. We do not book surveys and we do not guarantee any outcome.

Check your eligibility at instantgrant.co.uk