Meters and readings
SMETS1 vs SMETS2 smart meters: what is the difference?
How SMETS1 and SMETS2 smart meters differ, why it matters when you switch supplier, and what it means for Octopus smart tariffs.
Edited by Rob Gibbs. Published: . Guidance reviewed: .
Short answer
Both record your usage automatically. The difference is how they talk to your supplier. SMETS2 meters use the national DCC smart network, so they stay smart when you switch supplier. SMETS1 meters were built to talk to the supplier that fitted them. Many have since been moved onto the DCC network, but those that have not can lose their smart features when you switch.
How each type communicates
SMETS1 meters were the first generation. Each supplier ran its own system, so the meter sent data only to the company that installed it.
SMETS2 meters connect through the Data Communications Company (DCC), a single network overseen by Ofgem that all major suppliers use. Any supplier on that network can read a SMETS2 meter, which is why it keeps working after a switch.
What happens when you switch
A SMETS2 meter carries on sending readings to your new supplier. A SMETS1 meter that has been enrolled onto the DCC network will usually do the same. A SMETS1 meter that has not been enrolled often falls back to non-smart mode: it still measures your energy, but you need to send readings yourself.
Why it matters for smart tariffs
Agile, Go, Intelligent Go, Cosy, Tracker and the export tariffs all depend on Octopus receiving reliable half-hourly readings. A meter that has gone dumb cannot support them, whatever its label says. Check the meter is communicating before you choose one of these tariffs.
How to tell which one you have
Your supplier can tell you from its records, and many meters show the type on a label. A useful practical test: if your bills show actual readings you did not send, the meter is communicating. If they show estimates, it is not, whatever generation it is.
Octopus is replacing some SMETS1 meters with SMETS2 ones, partly because the communications hub in some SMETS1 meters cannot be upgraded.
Questions people ask
Can I go on Agile with a SMETS1 meter?
Possibly, if Octopus can read it every half hour, which usually means it has been enrolled onto the DCC network. Ask Octopus to check the specific meter before relying on it.
Will a SMETS2 meter ever stop working after a switch?
It is designed not to, but communication faults still happen. If readings stop arriving, report it and send manual readings in the meantime.
Tariffs in this guide
Related guides
- Octopus smart meter not sending readings: what to checkWhy a smart meter stops sending readings to Octopus, how to check it, and how to keep your bills and smart tariff on track while it is fixed.
- What is Octopus Energy? Tariffs and how it differsA plain-English introduction to Octopus Energy: who it is, the kinds of tariff it offers, and how to find the right one for your home and region.
- What happens to your smart meter when you switch to OctopusWhether your smart meter keeps working when you switch to Octopus, why some older meters go dumb, and what to do about it.
- How to see and download your smart meter dataWhere to find your half-hourly smart meter data from Octopus: in the app, through the free API, and with this site’s private usage tools.
- Single-phase vs three-phase home EV chargingWhy most home EV chargers run at around 7kW, when three-phase charging helps, and why a faster charger rarely matters on an overnight tariff.
- Free electricity from Octopus: how the sessions workHow Octopus’s power-up sessions, Postcode Power Ups and Agile negative prices give you free or cheap electricity, and what you need to join.
Primary sources
- SMETS1 vs SMETS2: why the upgrade matters — Octopus Energy; checked 2026-10-30. SMETS1 and SMETS2 differences, DCC enrolment and smart mode after switching supplier.
- Joining an Octopus smart tariff — Octopus Energy; checked 2026-08-27. Smart-meter connectivity, half-hourly readings, installation and compatibility limitations.