Smart meter overcharging and clock changes

Daylight Saving Time (DST) changes can lead to unexpected energy bill discrepancies for smart meter users, particularly those on multi-rate tariffs like Economy 7. While most modern smart meters adjust automatically, older models or connectivity issues can cause problems. Understanding how your meter functions and actively monitoring your energy use is crucial to prevent potential overcharging.

Fuse Energy helps you maintain control over your energy usage and bills, even with seasonal clock changes. Our digital-first approach provides clear insights into your consumption, ensuring accuracy and empowering you to make informed decisions. Click here to switch to Fuse Energy today.

How clock changes affect smart meters

Smart meters are designed to streamline energy billing by providing accurate, real-time data, removing the need for manual readings. However, the bi-annual clock changes can introduce complexities that affect how your meter records consumption.

Automatic adjustment for modern smart meters (SMETS2)

Most modern smart meters, known as Second Generation Smart Meters (SMETS2), are built with the capability to automatically adjust for DST changes in spring and autumn. This means they should seamlessly update their internal clocks to reflect British Summer Time (BST) or Greenwich Mean Time (GMT) without any manual intervention. This automatic adjustment is vital for accurate billing, particularly for tariffs that charge different rates at different times of the day.

Challenges for older smart meters (SMETS1)

Older smart meters (SMETS1 models) or those experiencing connectivity issues may not adjust their internal clocks automatically. If your smart meter is not working correctly or has lost connection, it might not receive the necessary updates to synchronise with the new time. This can lead to your energy usage being recorded against incorrect time periods, potentially causing billing errors. Some older meters might display the wrong time, even if they are still sending readings, which can cause confusion.

Economy 7 and multi-rate tariffs: a special concern

Customers on multi-rate tariffs, such as Economy 7, are particularly vulnerable to overcharging if their meter's time settings are incorrect after a clock change. These tariffs offer different rates for peak and off-peak electricity consumption, typically with cheaper rates overnight.

Why accurate timekeeping is crucial

Economy 7 tariffs rely heavily on accurate timekeeping to correctly apply peak and off-peak rates. If your smart meter's clock fails to adjust for DST, it might continue to record energy used during the new off-peak hours at the more expensive peak rate, or vice versa. This can lead to an unexpected increase in your energy bill, even if your consumption habits have not changed. It is a common concern that can result in an "Economy 7 smart meter glitch" if not addressed promptly.

The impact of the radio Teleswitch service (RTS) phase-out

A significant factor for some multi-rate meter users is the ongoing phase-out of the Radio Teleswitch Service (RTS). RTS meters are a legacy system that uses a longwave radio signal to switch between peak and off-peak rates. The signal switch-off began on 30 June 2025, meaning these meters are being retired and replaced. If you have an RTS meter, your current energy supplier is responsible for replacing it with a smart meter, usually free of charge. Failure to replace an RTS meter could lead to issues with heating or hot water supply and incorrect billing as the service is discontinued.

Common smart meter problems during time shifts

Beyond clock synchronisation, several other smart meter problems can arise during time shifts, contributing to concerns about overcharging or inaccurate billing.

Smart meter not sending readings

One of the most frustrating issues is when your smart meter is not sending readings to your energy supplier. This can happen due to connectivity problems, a faulty meter, or if the meter was never properly commissioned. If your meter is not sending readings automatically, your supplier may resort to estimated bills, which might not reflect your actual usage and could lead to a scenario where your electric bill is higher than expected.

Smart meter display not working

A smart meter display not working or an in-home display (IHD) showing incorrect information can be a clear indicator of an underlying problem. While the IHD is separate from the meter itself, a blank or faulty display can mean you are losing visibility into your energy consumption. Without easy access to your real-time usage data, it becomes harder to monitor for discrepancies after a clock change or to identify if your smart meter has stopped working entirely.

Incorrect meter serial number or not commissioned

Sometimes, issues stem from administrative errors, such as an incorrect meter serial number recorded by the supplier, or a smart meter not commissioned properly during installation. A meter that has not been fully commissioned might not be communicating correctly with the network, leading to problems with sending readings or receiving time updates. These issues can make it seem like your smart meter is wrong when the problem lies in its setup or data management.

Your step-by-step guide to preventing overcharging

Proactive steps can help you avoid smart meter overcharging clock change issues and ensure your energy bills remain accurate.

Before the clock change: prepare your meter

1. Verify your smart meter type: Determine if you have a SMETS1 or SMETS2 meter. SMETS2 meters are generally more reliable for automatic time adjustments. If you are unsure, your energy supplier can tell you.
2. Check your meter's status: In the days leading up to a clock change, ensure your smart meter's in-home display is working and showing current readings. If you have an online account with your supplier, check that your meter is registered as 'online' and sending readings.

During the change: monitor and record

1. Monitor multi-rate tariffs: If you are on an Economy 7 or other multi-rate tariff, pay close attention to your peak and off-peak timings immediately after the clock change. Verify that the correct rates are being applied during the new time periods. Your supplier's app or online portal might show this information.
2. Take a manual meter reading: On the day of the clock change, take a manual reading from your physical meter. This provides a valuable backup in case any discrepancies arise later. Note down the time and date of the reading.

After the change: verify your billing

1. Contact your energy supplier immediately: If you notice any discrepancies with your meter display, readings, or tariff timings, or if your gas smart meter is not sending readings, contact your energy supplier without delay. They may be able to resolve issues remotely or schedule an engineer visit.
2. Review your first bill: Carefully check your first energy bill after the clock change for any signs of overcharging or incorrect tariff application. Compare it with previous bills and your manual readings. According to Ofgem, the average UK household uses 2,700 kWh of electricity per year, so significant deviations could indicate a problem.

What to do if you suspect an issue

If you suspect your smart meter is not working correctly or you are being overcharged, taking swift action is important.

Troubleshooting a non-working smart meter

If your smart meter is not working or has stopped working, first try a simple restart of your in-home display (if applicable) by turning it off and on again. Check for any error messages on the meter itself. Ensure the meter has not lost power or connectivity. If these basic steps do not resolve the issue, it is time to contact your supplier.

Contacting your energy supplier

Your energy supplier is your first point of contact for any smart meter issues. They are responsible for ensuring your meter functions correctly and that you are billed accurately. Clearly explain the problem, providing any manual readings or observations you have made. Ofgem, the energy regulator, sets rules for suppliers to ensure fair billing practices, including those related to smart meters and time changes.

Understanding your rights and recourse

If you are not satisfied with your supplier's response, you have further recourse. You can escalate your complaint through their internal complaints procedure. If the issue remains unresolved after eight weeks, or if you receive a deadlock letter, you can take your complaint to the Energy Ombudsman, an independent body that can help resolve disputes between consumers and energy companies.

At Fuse Energy, we believe in empowering our customers with the tools and information needed to manage their energy effectively and avoid concerns like smart meter overcharging. The Fuse app provides real-time data and intuitive tools to monitor your smart meter's status and energy usage. This means you can easily check if your meter is online, sending readings, and accurately reflecting your consumption patterns, especially around clock changes. Clear visibility helps you detect and prevent billing discrepancies before they become a problem. Our commitment to "never settle" on the status quo means we provide transparent, easy-to-understand billing information directly through the app. You have clear visibility into your energy consumption and how it translates to your bill, reducing anxiety around clock change issues and ensuring you are always charged correctly. Should you encounter any issues with your smart meter or have billing concerns arising from clock changes, Fuse offers 24/7 human customer support via the app. This means immediate assistance is just a tap away, providing peace of mind and ensuring you are never left to navigate complex energy issues alone. Click here to switch to Fuse Energy today.