Losing your mobile phone can be traumatic, but losing your phone numbers can be devastating, especially if you haven't backed them up or written them down on a piece of paper.

There are several methods for backing up your numbers but the easiest and probably best method is using a SIM card backup kit. There are two types of kit: the first uses your computer and a USB SIM card reader to download your phone book on to your computer, and the second simply uses a SIM card reader.

If you choose the first method, all you need to do is load the software that comes with the kit on to your computer and then attach the USB SIM reader (pictured below) to it. Then you take out the SIM card from your phone and put it in the reader.
 

 
You can then back it up using the provided software -- this will usually create a backup file. The best way to keep this file safe is to keep a copy on your computer and also email it to yourself. You must make sure that you keep the kit safe, as you will need it to restore your numbers to a new SIM card if you lose the old one.

The second method uses a SIM card reader (pictured below) that is usually pretty small and fits on a key ring. This device provides a similar service to the one above but works independently of a computer and it can usually only store one phonebook, whereas the computer method will let you download as many people's phonebooks as you like.

There are SIM readers of this type that will store more than one set of numbers, but always check before you buy one. These devices work by placing your SIM card into the reader and pressing a button, which automatically backs up your numbers. The numbers are then stored on the device and you can place another SIM card into it and restore those numbers with the simple press of a button.