In the context of energy, a collective is a tariff from a supplier that’s only available exclusively to a specific group of customers. This doesn’t mean an informal group, like friends or neighbours – it’s more organised than that. In the past, collectives have been arranged by councils, national newspapers and, of course, comparison sites for their customers. It's often referred to as collective energy switching.
All energy suppliers are required by Ofgem (the energy suppliers’ regulatory board) to make the information on their bills as clear as possible. A personal projection is an estimate of how much energy you’re likely to use and pay for over the next 12 months, based on your previous usage.
With a pre-payment meter you pay as you go for your energy by putting credit on your account before you use it, rather than receiving bills after power has been used. Typically money is added on to a key or smart card, which is then inserted into the meter. They can be topped up at a local Post Office, PayPoint, or corner shop that has the technology. Some can be topped up by mobile phone. Many households use them to help manage their energy use and to budget. However, tariffs for prepayment meters can be higher than others.