Why does MCS terminology vary?
Search for an MCS installer online and you will quickly encounter several different descriptions. Companies may be referred to as MCS certified installers, approved installers, registered installers or accredited installers.
These phrases are often used conversationally to refer to businesses connected with the Microgeneration Certification Scheme, but that does not mean every phrase is the formal description of the same thing.
If you are researching an installation company, the wording used in a search result or company description is less important than verifying the underlying certification information.
MCS certified installers
MCS certified installer is the clearest term to use when referring to an installation company certified under the MCS scheme for relevant microgeneration or low-carbon technologies.
Certification may relate to one or more technologies. That means two MCS certified companies do not necessarily provide the same services.
For example, one installer may work with Solar PV and battery storage while another specialises in air source or ground source heat pumps.
If you want a broader introduction, start with our complete guide to MCS certified installers in the UK.
What are MCS approved installers?
MCS approved installers is a phrase commonly used by people looking for installation companies that meet MCS requirements.
In everyday searches, the word "approved" may simply be used as a substitute for "certified". It is therefore better to check the actual certification information rather than assuming that the word approved describes a separate installer status.
This matters particularly when comparing companies. A general claim that a business is "MCS approved" does not by itself tell you which technology the certification relates to or whether the information you are viewing is current.
What are MCS registered installers?
MCS registered installers is another common search phrase used when people want to find companies appearing within the MCS installer ecosystem.
The term "registered" can sound as though it describes a specific level of certification, but it is often used more generally when referring to companies listed or recorded as MCS installers.
For research purposes, it is more useful to look at identifiable fields such as the installer name, certification number, certification body, technologies and areas served.
What are MCS accredited installers?
You may also encounter the phrases MCS accredited installers and list of MCS accredited installers when searching for companies.
"Accredited" is frequently used in general conversation about certification schemes, but it should not be assumed to be interchangeable with every formal certification term.
If your objective is simply to identify companies working within the MCS market, these terminology differences may be relatively minor. If your objective is to establish whether a particular installer currently holds the certification needed for a project, the underlying certification details are what matter.
What should you actually check?
Whether you searched for an approved, registered, accredited or certified installer, there are several useful pieces of information to consider when researching a company.
- Company name - identify the actual installation business.
- Certification number - useful for distinguishing and checking installer listings.
- Certification body - identifies the relevant certification body recorded for the installer.
- Technology - check whether the certification relates to Solar PV, heat pumps, battery storage or another technology.
- Location and service region - establish whether the installer operates in the area relevant to you.
- Current status - certification information can change, so verify current details where status is important.
Technology is particularly important. Being associated with MCS does not mean that a company installs every technology covered by the scheme.
For technology-specific research, see our guides to MCS solar installers and MCS heat pump installers.
For totals of MCS installer listings by technology and county, see Data Menu's technology study and geography study. These show counts only, not individual installers.
Finding MCS installer information
The right way to find installer information depends on what you are trying to achieve.
If you are a homeowner looking for a company to complete an installation, your priorities are likely to include technology, location, suitability for the project and current certification.
If you are a business researching the market, building a supplier list, analysing the renewable energy sector or identifying installation companies at scale, structured installer data can be more practical than checking companies individually.
Our guide to finding MCS certified installers explains these approaches in more detail.
The simplest approach is not to get too caught up in the wording. "Approved", "registered" and "accredited" may appear in searches and informal descriptions, while the useful question is what current MCS certification the installer actually holds and which technologies it covers.
Figures are Data Menu's count of installer listings shown in the public MCS 'Find an Installer' search, grouped by county and technology, as at 15 October 2026. This is independent analysis, not official MCS statistics. Data Menu is independent of MCS and is not the official MCS directory. To find an installer or check current certification, use the MCS Find an Installer search, especially where it matters to an installation, purchasing, eligibility or compliance decision.