SMETS1 vs SMETS2 smart meters

Smart meters come in two generations. The label matters because it can affect whether your meter keeps sending automatic readings when you switch supplier, and whether Octopus can use it for smart tariffs such as Agile, Go, Intelligent Go and Cosy.

The short version: SMETS2 is the newer, more interoperable standard. Many SMETS1 meters have now been migrated onto the national smart-meter network and work properly after a switch, but some older SMETS1 setups can still lose smart functionality or need replacing. In 2026, the extra reader question is not only whether it will stay smart after a switch. It is also whether the meter and communications hub are ready for the move away from older 2G and 3G networks.

• Octopus says it is replacing older SMETS1 meters with SMETS2 where the integrated 2G or 3G communications hub cannot be upgraded for the newer 4G smart-meter network.
• DCC still says almost all dormant SMETS1 meters it can proactively identify and upgrade have been migrated, but remaining problem meters need supplier involvement and may need a SMETS2 replacement.
• Citizens Advice and Ofgem both point households to the smart-meter checker before switching, because the practical issue is whether the meter should work in smart mode after a supplier move.
• Octopus smart-tariff terms still depend on a compatible smart meter and half-hourly readings, so third-party app evidence cannot replace Octopus meter data for billing.

What the names mean

SMETS1 means Smart Metering Equipment Technical Specifications, first generation. These were the early smart meters, commonly installed during the first phase of the UK rollout.

SMETS2 is the second generation. These meters were designed to communicate through the national smart-meter network from the start, rather than being tied to one supplier’s own systems.

The names are standards, not model names. There are many physical electricity and gas meter models within each generation, so the front of the meter will not always say SMETS1 or SMETS2 clearly.

What actually matters when you switch

Older SMETS1 meters were originally built to talk to the supplier that installed them. When a household switched supplier, some of those meters carried on measuring energy accurately but stopped sending automatic readings to the new supplier. That is the old “smart meter gone dumb” problem.

SMETS2 meters use the Data Communications Company, usually called the DCC, which runs the national smart-meter network. DCC says SMETS2 meters should normally keep sending readings and update supplier and tariff details remotely when you switch.

The picture for SMETS1 is more mixed. The DCC has migrated millions of first-generation meters onto the same wider network, so an enrolled SMETS1 meter can often behave much like a SMETS2 meter for everyday switching and billing. If a SMETS1 meter has not been enrolled, Citizens Advice says your new supplier might not be able to read it automatically after a switch.

How to check what you have

Start with the practical status, not just the label:

1. Use the Citizens Advice smart meter checker. It can tell you whether your meter should work in smart mode and whether it is likely to keep working if you switch supplier.
2. Check your account or app. Your supplier may show meter details, smart-read status or recent automatic readings.
3. Look at bills. Repeated estimated readings after setup can be a sign that the supplier is not receiving smart data.
4. Check the installation date only as a clue. A pre-2019 installation is more likely to be SMETS1, while newer installations are usually SMETS2, but the date alone is not proof.
5. Ask the supplier if you are unsure. Give them the meter serial number and ask whether the meter is enrolled, communicating and suitable for half-hourly readings.

If you have just switched, allow a short setup period. Citizens Advice says readings can take a few weeks to appear on bills after a recent supplier switch or account setup.

The SMETS1 enrolment programme

The SMETS1 enrolment programme was created to move first-generation meters onto the DCC network so they could keep working across suppliers. DCC says almost all dormant meters it can proactively identify and upgrade have now been migrated, while remaining problem meters need supplier involvement.

That means old advice saying “SMETS1 always goes dumb when you switch” is no longer accurate. Some SMETS1 meters work fine. The safer question is whether your specific meter is enrolled and communicating.

There is now a second future-proofing point as well. Octopus says some older SMETS1 meters have integrated 2G or 3G communications hardware that cannot simply be swapped for the newer 4G communications hub. Where that is the issue, Octopus says it will need to replace the SMETS1 meter with SMETS2 rather than just update the hub.

If a SMETS1 meter cannot be migrated or future-proofed cleanly, DCC and Octopus both point back to the supplier arranging a SMETS2 replacement. That is different from asking for a replacement just because the meter is labelled SMETS1. The trigger is whether it is communicating, enrolled and suitable for the smart tariff or future network change you need.

Does it affect Octopus tariff options?

Yes, because Octopus smart tariffs depend on reliable smart-meter readings. If you want Agile, Go, Intelligent Go, Cosy or a similar time-of-use tariff, the important requirement is a compatible smart meter that can send the right reading data.

An enrolled SMETS1 meter may be enough if it is sending readings reliably. An unenrolled or non-communicating SMETS1 meter may block smart-tariff setup until it is enrolled, fixed or replaced. Octopus’s smart-tariff terms also say customers agree to half-hourly meter readings. If readings are missing, Octopus can estimate only within the limits of those terms, and third-party charger, car, battery or app records are supporting evidence rather than the final billing record.

The standard Flexible tariff can still work with manual readings, but that misses the point if you are switching mainly for a smart tariff.

Flux also depends on smart export/import data. Octopus now presents standard Flux as a solar-and-battery import/export tariff that needs a smart meter with half-hourly readings, export paperwork and a battery schedule, while Intelligent Octopus Flux is the separate route where Octopus controls a compatible battery. If you are comparing solar options, use the export rates guide rather than assuming an old Flux reference still applies.

Should you request a replacement?

If your SMETS1 meter is enrolled, communicating and Octopus can receive the readings it needs, there may be no urgent reason to replace it. A working meter is more important than the generation label.

A replacement becomes more relevant if:

• your supplier cannot receive automatic readings after the setup period
• bills are repeatedly estimated
• Octopus says the meter cannot support the smart tariff you want
• Octopus or your supplier says the integrated SMETS1 communications setup cannot be future-proofed for the 4G smart-meter network
• the meter is one of the remaining SMETS1 setups that cannot be migrated cleanly
• you have an old non-smart meter and want smart-tariff access

Citizens Advice says you should contact your supplier if the meter is not working as it should. If there is a communication problem, the supplier should investigate rather than leaving you with indefinite estimated bills.

What to do before switching to Octopus

If your meter is already sending readings and your bill is not estimated, switching should usually be straightforward. Keep an opening reading anyway, because your first bill and final bill with the old supplier still need a clean handover.

If the smart-meter status is unclear and you want a smart tariff, check before you rely on the tariff saving. Ask Octopus whether your electricity meter is compatible, whether it can receive half-hourly readings and whether you should book a meter exchange after the switch.

For the wider handover, read what happens to your smart meter when you switch. For display-screen problems, use the in-home display guide, because a faulty screen is not the same thing as a faulty meter.

If you decide Octopus is still the right fit after those checks, you can use the referral link when you switch.