ENA-Registered Inverters: Why It Decides Whether Your Kit Is Legal

What is the ENA type test register?

It is the public list of generation equipment that has passed type testing against the connection standard used in Great Britain. Each entry is a test report for a specific model, submitted by the manufacturer.

The distinction people get wrong is what is listed. The register covers equipment: an inverter model with a model number. It does not certify retailers, importers or installers. Any seller telling you that they are ENA registered has described it incorrectly, and that is worth noticing.

How do I check if an inverter is ENA registered?

Get the exact model designation from the listing or the datasheet, then search the register for it. It takes under a minute and you can do it before you part with any money.

1. Find the full model number — not the brand, not the wattage. "800W micro inverter" is not a model number.
2. Open the ENA type test register and search that model.
3. Check the entry is for the same variant. Manufacturers often have close siblings where only one is listed.
4. Check the rated output matches the 800VA / 3.5A ceiling.
5. If you cannot find it, ask the seller for the type test report reference. A compliant supplier will have it.

Source: the ENA type test register is published at ena-eng.org/gen-ttr.

What if the inverter is not listed?

Then the installation does not meet the connection conditions, whatever the product page says. That is the plain factual consequence, and it does not change because the kit was cheap or because it physically works.

What that means for any individual home insurance policy is a question for your insurer rather than for us. We would only say this: it is a much easier conversation to have before you buy than after something has gone wrong.

The inverter we supply: Hoymiles HMS-800-Pro

Cheaper 800W micro inverters exist; this one is on the ENA register, and that is what we pay for. It is listed, it arrives with a UK plug already moulded on, and the monitoring is genuinely useful rather than a token app.

Why registration is about to get slower

Type testing and listing took months before the law changed. Now that plug-in solar is legal across Great Britain, a great many manufacturers have a commercial reason to get listed at once.

The practical consequence for a buyer is simple: a model that is listed today is a safer purchase than a model whose seller says listing is "in progress".

Questions worth asking any seller

• What is the exact inverter model number?
• Can you point me at its entry on the type test register?
• Is the plug factory-moulded, or fitted afterwards?
• What fuse is in it?
• How long is the inverter warranty, and who honours it in the UK?
• If it fails in year four, who do I contact?

Frequently asked questions