There are two types of tariffs you can choose from: variable or fixed. One is more flexible and the other offers benefits but with you agreeing to lock into typically lower prices. Here is a little more information on what these options mean for you.
A fixed tariff is a contractual relationship where you agree to the price of energy for a specific length of time, similar to a mobile phone contract, usually this is 1-2 years. Your prices won't change so are protected against the market. If you decide to leave early, it could mean paying exit fees. These exit fees are usually stated clearly in your tariff information pack.
A variable tariff on the other hand, has no end date. The rates of energy cost can be varied according to the wholesale market. There is a possibility that prices will go down, but there is also a possibility prices will go up. With variable tariffs there are no exit fees, no end date, and no protection against the market.
How can I choose which one I want?
You can choose whether you're happy to switch to just fixed tariffs, or whether you're happy to switch to either by visiting your Switchd dashboard. Simply go to your user settings and you'll see the following options, circled in red is the setting you can change to opt in, or out, of variable tariff switches.