Why is the quantity on the CASS 3553 form different from the simple-mailable file?

Question

Shouldn't the simple-mailable file have the same results as the CASS form?

Answer

This is normal. The number of CASS certified address (total) includes duplicate and vacant addresses. We remove those when creating the "simple-mailable" file.

So, if you process 1000 addresses and 975 of them are CASS-certified to be valid addresses, this would include the vacant addresses and also the duplicate addresses that we remove. So, the mailable file in this example might be only 900.