The Price Cap applies to 'default' tariffs – ones you don't actively choose to switch to – whether you pay by direct debit, cash or cheque, or prepayment. These tariffs are generally known as standard variable tariffs (SVTs), and you'll be on one if any of the below apply.
But right now, due to the energy crisis, almost everyone is on a price-capped. You'll be on a price-capped tariff if:
You've never switched your energy tariff. You would have always been on your supplier's standard tariff, so you will be protected by the Price Cap.
You were on a fixed deal, but haven't chosen to switch again. If you have previously chosen a fixed deal, once the fix period ends you will be automatically rolled on to a price-capped tariff if you do nothing.
You were with a supplier that has gone bust. In most cases, if your supplier goes bust, your existing tariff with that supplier will end, and Ofgem will pick a new supplier to take over. Your tariff with the new supplier will be protected by the Price Cap.
In the past, we have seen some providers offering rates lower than the Price Cap when taking on customers from failed suppliers (such as when EDF took on Green Network Energy customers) – but this is unusual. Regardless of what rate you're offered, you can't be charged more than the Price Cap when being moved from a failed supplier.
You're moving home. Usually when you move home, your current tariff will end when you let your supplier know you're moving out (a few let you transfer fixed deals, so do check).
You'll then need to contact the existing supplier of the property you're moving into, to let them know when you moved in and to set you up with a new account. From the date you moved in, you'll be placed on a 'default' tariff, which is controlled by the Price Cap.
The Price Cap doesn't apply to fixed deals on the market – although if you're on a fixed-rate deal right now, you would have been getting a discount on your rates under the Energy Price Guarantee. However, from 1 July, the EPG fell away, meaning you'll no longer be getting a discount on your fixed deal, so you could see your prices rise.
The Price Cap also doesn't apply to any standard variable tariffs that have an exemption to the Price Cap (this is only for very green deals, and you still have to choose to be on them).