The CRM should be able to handle this at the time of import. You should be able to define a group of fields that represent a "key", i.e., together they form a unique record (only one can fill the criteria). At the time of import, you should be prompted for how you want to handle a duplicate (based on the key), i.e., delete, update/modify, etc.

If the CRM doesn't handle it, MS-Access can do the same thing for you in a similar fashion.

Peter

p.s. This is a good time to update mailing addresses, too. Either work with your local Post Office to send the list through for an update (a.k.a., sanitize the list), or there are many third-party software and services vendors that can do it for you, or use their product/service. This eliminates the re-do from putting dirty addresses into a clean database when it comes to mailing time.

Sales is more than just a numbers game...