There is quite a bit of confusion in the marketplace about removing duplicates (de-duping) from mailing lists. Below is a brief synopsis on how de-duping a mailing list works.
First, de-duping is not a standard part of the NCOA (National Change of Address) process or the CASS (Coding Accuracy Support System) certification. Our default de-duping procedure is by name, address, and zip. This means that all 3 fields have to match exactly in order for it to be a duplicate. This eliminates the same person at one address from getting multiple pieces of mail.
Below are some examples of de-duping options:
1) If you use our default (name, address, and zip) the de-duping process and all data is the same:
Thomas Jefferson Thomas Jefferson
521 Research Rd 521 Research Rd
North Chesterfield VA 23236 North Chesterfield VA 23236
Result: Thomas Jefferson would only receive one piece of mail.
2) If you use our default (name, address, and zip) de-duping process and address is different:
Thomas Jefferson Thomas Jefferson
521 Research Rd 2317 Woodmont Dr
North Chesterfield VA 23236 North Chesterfield VA 23235
Result: Thomas Jefferson would receive one piece of mail at each address.
3) If you would like one piece of mail per address, please request one per address and we would de-dupe by address and zip. This does not include an address2 or address3 field.
Thomas Jefferson George Washington
521 Research Rd 521 Research Rd
North Chesterfield, VA 23236 North Chesterfield, VA 23236
Result: Only the first record in the database would receive one piece of mail.
Thomas Jefferson George Washington
521 Research Rd 2317 Woodmont Dr
North Chesterfield VA 23236 North Chesterfield VA 23235
Result: Both Thomas Jefferson and George Washington would receive one piece of mail.
4) If you would like only one of the names to receive the mail piece, regardless of address, request to de-dupe by name only.
Thomas Jefferson Thomas Jefferson
521 Research Rd 521 Research Rd
North Chesterfield VA 23236 North Chesterfield VA 23236
Result: Thomas Jefferson would only receive one piece of mail.
Thomas Jefferson Thomas Jefferson
521 Research Rd 2317 Woodmont Dr
North Chesterfield VA 23236 North Chesterfield VA 23235
Result: Thomas Jefferson would only receive one piece of mail. * Note: This is different from example 2 using the same address information.