Last week we covered the types of lists you might use to create a mailing. This week we’re going to cover the types of sanitization needed to make those lists acceptable for mailing. The three most common are Coding Accuracy Support System (CASS), National Change of Address (NCOA), and duplicate removal.

For a mailing to receive automation discounts and carrier route discounts, it must be processed through CASS-certified software. This software takes each address and translates it to a USPS-acceptable form. For example, “45 South Main” might need to be changed to “45 S Main St” to qualify for automation discounts. At the same time, Zip+4 and delivery point data is added to the address for the automation processing. After the list is corrected, there is a certificate produced showing that the list complies with CASS requirements which must be presented to the postal service with your mailing.

Another requirement for all mailings containing actual names (as opposed to “Resident” or “Our Friends At”) is that they be compared to the National Change Of Address database maintained by the USPS. This database is updated every time someone notifies the post office that they have moved, either through the USPS website or by filling out a change-of-address card. Unlike CASS, there is no certificate for NCOA, but additional postage will be charged if your mail is tested and has too many missed address updates.

Outside of postal requirements, there is additional processing you may wish to have done. The most common is duplicate removal. When lists are merged from different sources (e.g. if you’re mailing to residents of a town, your existing customers, and sales leads you’re working on), there’s a very good chance you’ll end up with the same people in the list multiple times. The two most common ways to purge these duplicates out are by household (so only one goes to each address) or by name (so that an address may get multiple copies for different people).