Direct Debit is an instruction from you to your bank or building society, authorising the organisation you want to pay to collect varying amounts from your account – but only if you’ve been given advanced notice of the amounts and dates of collection.
Once you have agreed those, the money is deducted automatically. If the organisation you are paying wants to change an amount or date of collection, they have to tell you about it first.
It is generally used to pay regular bills automatically, such as gas, electricity and Council Tax.
Source: The Smart Way To Pay
Message supplied by: Rich @ Respect Yourself