SMETS1 vs SMETS2: Why the Upgrade Matters

According to the Department for Energy Security and Net Zero (DESNZ), there were around 39 million smart meters in homes and small businesses across Great Britain at the end of March 2025. This will be a mix of SMETS1 (first-generation) and SMETS2 (second-generation) smart meters, of which there are varying models by multiple manufacturers.

We’re now replacing SMETS1 meters with the newer models - the SMETS2.

Why are we upgrading SMETS1 smart meters with the new SMETS2 meters?

All smart meters have a communications hub. It’s usually located on top of your electricity smart meter or, in some cases, beside it. These hubs enable your smart meter to share data with your In-Home Display (IHD) and us, your supplier, via secure networks managed by the Data Communications Company (DCC). All comms hubs installed until recently were built on 2G and 3G cellular signals in the South and a long-range radio network in the North.

The government has announced the gradual phase-out or ‘sunsetting’ of the 2G/3G mobile networks. This ensures the UK is prepared for future technologies on 4G and beyond.

This means smart meters in the South with 2G and 3G communications hubs will be directly affected, and no longer function as smart after the full switch off in 2033.

According to DESNZ, at the end of 2024 there were 14 million SMETS1 meters in the UK. This means we need to act now, and upgrade these meters to be compatible with the new 4G network by 2G/3G switch off at the end of 2033.

SMETS2 smart meters that still have a 2G/3G hub are set to be fitted with a 4G hub as soon as possible and at no extra cost.

What are the main differences between SMETS1 and SMETS2?

Both types of smart meters automate the way your energy usage is recorded and shared with your supplier, but there are more differences than you may think:

• Connectivity
• Future-proofing
• Compatibility

Network and switching suppliers:

SMETS2 meters are connected via a single and secure digital network. It’s run by the Data Communications Company (DCC) and overseen by the energy regulator Ofgem. This means it must comply with strict regulations to ensure smart meter data is kept private and secure. This smart meter network links all major energy suppliers across the UK, meaning that customers with SMETS2 meters can move seamlessly between suppliers without losing smart functionality.

While on this network, SMETS2 meters can send and receive over 150 types of messages, including meter readings, service firmware updates and upgrades. This makes them ideally placed for changes in the energy grid.

They are also compatible with the rollout of the new 4G communication hubs, which are the answer to the government's gradual phase-out of the 2G/3G networks.

SMETS1 meters, when installed, only communicated with the supplier who installed them and shared data directly with them. Over the last few years, SMETS1 meters have been gradually enrolled onto the DCC network to improve their connectivity. However, with their older software, they benefit from fewer firmware upgrades compared to their SMETS2 counterparts and are more limited in their features.

SMETS1 meters that have not been enrolled on the DCC network often go into ’non-smart mode' when switching suppliers. This means you will need to submit manual readings. These meters will need to be upgraded to a brand new SMETS2 meter.

Future-proofed for a flexible smart grid:

As mentioned, SMETS2 smart meters are connected via a nationwide network run by the DCC. We all know the future of energy relies on utilising renewable energy sources such as solar panels and wind turbines. It is therefore essential to have a smart energy network which can communicate efficiently across the UK and respond to the needs of the grid.

This network allows for regular remote upgrades and is future-proofed for changes in the grid.

Aside from the obvious issue of having integrated 2G communication hubs, we know that SMETS1 smart meters also have a more limited ability to receive remote updates and requests due to their older software. The creation of a growing number of smart tariffs, schemes, and time-of-use trials necessitates technology that can dynamically respond to grid changes. SMETS2 are perfectly prepped to allow customers access to the best money-saving and planet-friendly smart products—a win-win for you and us.

Compatible with the smart home:

SMETS2 meters are designed to work seamlessly with modern energy systems, including smart tariffs and smart home tech such as batteries, wind turbines, solar panels and electric cars.

The 4G network ensures that customers can benefit from this tech beyond the 2G/3G switch-off. This extends to things like smart thermostats (Nest, Hive, etc.), smart plugs and appliances and home automation platforms (like SmartThings).

SMETS1 vs SMETS2: At a glance