After lots of waiting on the phone. When your existing contract runs out, you will have to pay meter rental if you have a gas meter (even if you don't use gas). (£100/year in my case)
The only way to avoid this is to have the meter removed. They threatened to charge me £87 to do this (or I have to get a gas safe engineer to do it.) But as I'm over 60, it's FOC.
So, look out.