Because every contract is for a fixed amount of time, you're tied into the agreement until it expires and can't cancel or change it. The time frame will depend on your agreement with 12 months being the minimum. Smaller businesses receive reminders about when their contract is due to expire. This is the point at which you can search for a cheaper deal. If you find a deal that you prefer with a different supplier then you can accept it and inform your existing supplier that you want to close your account. Once your contract expires, you will be sent a final bill to pay and may be asked to send a final meter reading.