A fixed penalty notice is issued to speed up the paperwork involved in minor traffic offences to prevent them ending up in court. Your local police website will more than likely have details about what to do if you misplace your fixed penalty notice (speeding ticket or any other type of ticket). However, not all of them do have comprehensive information, in which case, do the following:
If you know which station the police officer is from that issued you the ticket you can go to that station, taking your documents with you (proof of identity, vehicle documents). The most likely thing will be that you will then receive a summons in the post so you can be dealt with by the court. You can then either plead guilty by letter and pay the fine before it goes to court, or you can plead not guilty and attend court and defend yourself.
If you receive the ticket through the post then contact the Central Ticket Office of the police force concerned by using the non-emergency 101 number. Sometimes it might be called the Fixed Penalty Unit or Central Process Unit. Give them the registration number of the vehicle you received the ticket in and the date and approximate time and they will usually be able to send another ticket. If you have to supply any documents, send them by registered post only otherwise you might not see them again. If the deadline has expired then it will be up to the person at the ticket processing department whether they want to prosecute or not.
If you received a fixed penalty notice from your local council, you’ll need to contact them.