What is a smart meter?

How a smart meter works

A smart meter measures your gas and electricity use and sends the readings to your supplier automatically over a secure mobile network. That means no more manual readings and no more estimated bills. Most come with a small in-home display that shows your usage and spend in near real time.

What you get out of it

• Accurate bills. You pay for what you actually use, not an estimate.
• Visible spend. The display shows what your energy is costing through the day, which makes it easy to spot what is driving the bill.
• Access to smarter tariffs. Some of the cheapest deals, including off-peak and time-of-use tariffs, need a smart meter to work.

SMETS1 vs SMETS2

Early smart meters (SMETS1) sometimes went "dumb" when you switched supplier, losing their smart features. The second generation (SMETS2) keeps working across suppliers because it connects to a shared national network. Most older meters have now been upgraded remotely, but if yours stopped sending readings after a switch, ask your supplier to check.

Do you have to have one?

No. Smart meters are offered to every home but they are not compulsory. If you would rather not have one, you can keep submitting manual readings. Bear in mind some of the better-value and off-peak tariffs are only available with a smart meter.

Privacy and accuracy

You control how often detailed data is shared, and the readings are sent over a dedicated secure network, not your home broadband. If a bill ever looks wrong, the in-home display and your online account let you check the readings yourself.

The bottom line

A smart meter ends estimated billing, shows you where your money goes, and opens up tariffs you cannot otherwise get. It is free to have fitted. If you are weighing up a new deal, having one fitted can widen your options when you next compare energy deals.