Most of the prepayment meters are single rate, meaning that you pay the same for electricity and gas regardless of what time you use it. It is a plan that can therefore be more expensive in terms of energy supply.
The meters can sometimes be inconveniencing because you need to be keen and have credit at all times to avoid disconnection when you least expect. This means that you need to have everything in order even when you are sick to avoid disconnection.
The advantages of prepayment meters outweigh the disadvantages and it might be a good idea to consider having them installed. Some energy companies are now phasing out the old meters and embracing the prepayment meters and you can easily make a switch if you feel they are the best option for your energy needs around the home.