Q213: What will happen if I don't pay the fine on a fixed penalty notice?
There are two ways of failing to pay a fine on a fixed penalty notice:
You reject the fixed penalty notice from the start. You will receive a summons to go to court. You can either then plead guilty by letter or elect to go to court. If found guilty at court you may be given a slightly larger fine and you will have to pay the court costs (approximately £40).
You accept the penalty notice but then fail to pay. The fine is registered with the court and is automatically increased by 50%. It is then for the court to enforce the fine and they do have the option of issuing a warrant for your arrest if you fail to respond.