Most smart meters installed today are 1st generation smart meters (SMETS 1) which communicate only with the energy supplier that provided them.
2nd generation smart meters (SMETS 2) are starting to roll out which all suppliers can automatically connect to.
This means that switching with a 2nd gen smart meter is a much smoother process since your meter doesn't lose any functionality when connecting to a new supplier.
Switching is absolutely possible with a 1st gen smart meter, however, it's likely that your new supplier will then need to operate it as a traditional meter with readings taken manually (by you).
If you are trying to figure out if you should get a smart meter and your supplier can only provide a 1st gen meter, it’s still worth getting one, as you can get smart functionality for the time you are with that supplier. Then, if you decide to switch suppliers in future, you may temporarily lose that smart functionality, but starting in 2019, the SMETS 1 meters should be upgraded and will work with all suppliers. 👍
For the full article, please read our blog post: Switching Energy Providers with a Smart Meter - a Guide.