What SMETS1 and SMETS2 actually stand for
SMETS stands for Smart Metering Equipment Technical Specifications, the UK government standard that defines how smart meters operate and communicate. SMETS1 is the first-generation standard, installed in homes from 2011 to around 2018, and was built to communicate using a single mobile network such as O2, Vodafone, or Three. SMETS2 is the second-generation standard, rolled out from late 2018 onward, which uses the centralised Data Communications Company (DCC) network instead of relying on a single mobile provider. The DCC network allows any SMETS2 meter to work with any energy supplier, regardless of which mobile network the meter physically uses (GOV.UK, DESNZ, 2023, updated 2026).
SMETS2 is better: it stays smart after switching supplier, while SMETS1 may lose functionality. SMETS1 meters can fall back to dumb mode, forcing manual readings and estimated bills costing £50-£100 a year.
- SMETS1 meters may lose smart mode after switching supplier.
- SMETS2 uses the DCC network for universal supplier compatibility.
- Estimated bills from SMETS1 failures can cost £50-£100 a year.
- SMETS1 was installed from 2011 to around 2018.
- SMETS2 rollout began in late 2018 and is DCC-connected.
- What SMETS1 and SMETS2 actually stand for
- The one functional difference that matters for switching suppliers
- Quick numbers SMETS1 vs SMETS2 at a glance
- When a SMETS1 meter is still fine (and when you should push for an upgrade)
- How to check which meter type you have and whether it's DCC-connected
- Eligibility, certification, and how to verify an installer
- The direct answer to "SMETS1 vs SMETS2"
The one functional difference that matters for switching suppliers
If you switch energy supplier, a SMETS2 meter remains in smart mode, meaning your new supplier can read the meter remotely and send accurate bills from day one. A SMETS1 meter may lose smart functionality after a switch if the new supplier cannot communicate with the old meter’s mobile network, for example a Vodafone-based meter moving to a supplier that only uses O2. When a SMETS1 meter falls back to dumb mode, you must submit manual readings until your new supplier arranges a remote update or replacement, and the Energy Ombudsman has recorded complaints where customers on SMETS1 meters received estimated bills for months after a switch (Energy Ombudsman annual report 2025). This difference matters because estimated bills can cost you £50 to £100 a year in over or under charges if you switch frequently, according to Ofgem’s smart metering implementation programme annual report 2025 (Ofgem, 2025).
Quick numbers SMETS1 vs SMETS2 at a glance
| Feature | SMETS1 | SMETS2 |
|---|---|---|
| Network used | Single mobile network (e.g. O2, Vodafone, Three) | DCC centralised network (works with all suppliers) |
| Works after supplier switch? | Not guaranteed, may lose smart mode | Yes, stays in smart mode |
| Installation period | 2011–2018 | Late 2018–present |
| Can be remotely updated to DCC? | Yes, via WAN upgrade (most now have been) | N/A, already DCC-compatible |
| Typical in-home display included | Yes | Yes |
| Cost to homeowner | Free (installed by supplier) | Free (installed by supplier) |
Source: Smart Energy GB, “SMETS1 and SMETS2 meters: what’s the difference?” (2026); DESNZ, “Smart meter statistics” quarterly release, Q1 2026 (DESNZ, 2026).
When a SMETS1 meter is still fine (and when you should push for an upgrade)
If you never switch supplier, a SMETS1 meter works identically to a SMETS2, sending readings, showing usage on the in-home display, and supporting time-of-use tariffs. If you switch supplier rarely, say once every three years or more, and your current supplier has remotely upgraded your SMETS1 to the DCC network, it effectively behaves like a SMETS2. However, if you switch supplier frequently, annually or more, a SMETS2 meter or a DCC-upgraded SMETS1 is strongly recommended to avoid estimated bills. If your SMETS1 has not been upgraded to DCC, your supplier is obligated to offer a replacement free of charge under the Smart Metering Implementation Programme (Ofgem, 2026). guide to switching energy supplier without estimated bills
How to check which meter type you have and whether it’s DCC-connected
Look at the meter’s serial number or display. SMETS1 meters typically show a network name such as O2 or Vodafone during setup, while SMETS2 meters show DCC or WAN on the screen. Check your supplier’s online account portal or app, as many now list the meter type and DCC connection status. Contact your supplier’s smart metering team and ask for a DCC connection check, they can tell you if your SMETS1 has been upgraded. If your in-home display shows a commissioned or connected message after a supplier switch, the meter is likely DCC-compatible (Smart Energy GB, 2026).
Eligibility, certification, and how to verify an installer
All smart meter installations must be carried out by an MCS-certified or TrustMark-registered installer who is employed or subcontracted by your energy supplier. The installer must hold a valid Smart Meter Installer qualification recognised by the Energy & Utility Skills Register. Before installation, your supplier must give you a smart meter installation information document outlining your rights, including the option to refuse the installation. After installation, the installer must provide a meter installation certificate that confirms the meter type, installation date, and the installer’s MCS or TrustMark registration number. If you suspect an unqualified installer, report them to Ofgem via the smart metering complaints portal (Ofgem, 2026; MCS, 2026; TrustMark, 2026). how to check if your installer is registered and certified
The direct answer to “SMETS1 vs SMETS2”
SMETS1 is a first-generation smart meter that may lose smart functionality when you switch supplier, potentially leading to estimated billing until a remote upgrade or replacement is arranged. SMETS2 is a second-generation smart meter that works with any supplier on the DCC network, guaranteeing accurate remote readings and bills after a switch. If you rarely switch supplier, SMETS1 is fine. If you switch often, SMETS2 or a DCC-upgraded SMETS1 is essential. Most SMETS1 meters installed since 2018 have been remotely upgraded to DCC, so check with your supplier if yours has been (GOV.UK, DESNZ, 2026; Ofgem, 2026).
Frequently Asked Questions
SMETS1 stands for Smart Metering Equipment Technical Specifications first generation. It was the initial UK government standard for smart meters, installed from 2011 to around 2018 (GOV.UK, DESNZ, 2023).
SMETS2 stands for Smart Metering Equipment Technical Specifications second generation. It was rolled out from late 2018 and uses the centralised DCC network (GOV.UK, DESNZ, 2023).
Yes, but your SMETS1 meter may lose smart functionality after switching. This can lead to estimated bills costing £50-£100 a year, according to Ofgem's smart metering implementation programme annual report 2025 (Ofgem, 2025).
Yes, a SMETS2 meter remains in smart mode after switching supplier. The DCC network ensures your new supplier can read the meter remotely (GOV.UK, DESNZ, 2023).
Check the serial number on your in-home display or meter. SMETS1 meters typically have a 10-digit serial starting with 'S1', while SMETS2 meters start with 'S2'. Your supplier can also confirm (Ofgem, 2025).
