How do I verify an installer?

Check TrustMark and MCS (or Gas Safe) on the official registers; read independent reviews.

Are 'free grant' cold calls real?

No — legitimate grants are free to apply for and never involve upfront fees or cold calls.

Choosing an Energy Efficiency Company

The right company makes the difference between a home that's warmer and cheaper to run, and a botched job. This guide shows how to verify a provider before you sign.

Last reviewed: August 2026

Check accreditations

For funded work: TrustMark + PAS 2035. For heat pumps/solar: MCS. For gas: Gas Safe. Verify on the official registers, not the company's own site.

Compare properly

Get 2–3 written quotes, check what's included (system upgrades, aftercare), and read independent reviews. Our company directory lists verified providers.

Red flags

Cold calls, upfront 'application fees', pressure to decide now, or no TrustMark/MCS registration. None of these are legitimate.

FAQs

How do I verify an installer?: Check TrustMark and MCS (or Gas Safe) on the official registers; read independent reviews.
Are 'free grant' cold calls real?: No — legitimate grants are free to apply for and never involve upfront fees or cold calls.