Data must not be kept longer than is necessary for the registered purpose.

It is alright to keep information for certain lengths of time but not indefinitely.  This rule means that it would be wrong to keep information about past customers longer than a few years at most.

There are legal rules for keeping data/information on company accounts and people health records but research is needed by a company to understand exactly what type of data is kept and for how long.

If data is to be stored for a long time it is strongly suggested that it is held in a secure storage facility similar to those provided by Secure Data Recycling.