List hygiene: dedupe, households, and the 95-day rule
Before an addressed mailing goes to the post office, the list has to be cleaned. Here is what CASS, DPV, NCOA and merge/purge mean, the USPS rule that requires it, and what cleanup does to your count and your bill.
A list straight from a vendor, a spreadsheet of past customers or a county voter file is rarely ready to mail. Some addresses are misspelled, some people have moved, and some homes appear twice. Cleaning the list fixes that before you pay to print and mail it. This guide is part of our direct-mail series; for the big picture, start with Direct Mail 101.
Four terms, one sentence each
CASS is the USPS certification for address-matching software, "designed in cooperation with the mailing industry to improve the accuracy of postal codes" (USPS PostalPro: CASS). In practice it checks and corrects the ZIP Code, ZIP+4, delivery point and carrier route on each address.
DPV (Delivery Point Validation) checks whether an address "is currently represented in the USPS delivery file as a known address record" (USPS PostalPro: DPV), which catches house and apartment numbers that don't exist.
NCOA (National Change of Address) matches your list against the change-of-address forms people file with USPS, about 160 million of them (USPS PostalPro: NCOALink), and swaps in the new address for anyone who moved.
Merge/purge combines lists and removes duplicates. The same software can "household" a list "by combining address records for several individuals living at the same address into a single entry" (Washington State DES).
The 95-day rule
USPS requires movers to be caught. Its Move Update standard says each address on presorted First-Class Mail and USPS Marketing Mail "must be updated within 95 days before the mailing date" (DMM 602.5.1). The approved ways to do it include NCOALink and USPS's own address-correction services (USPS PostalPro: Move Update).
The point of the rule, in USPS's words, is "reducing the number of mailpieces in a mailing that require forwarding or return". For you, it means a list cleaned in June is out of date for a mailing in October. Run NCOA again before each drop that falls more than 95 days after the last one.
Two kinds of mail skip the rule. The standard applies to Marketing Mail "except for mail bearing an alternative address format" (DMM 602.5.1). That covers Every Door Direct Mail, which is addressed to "Postal Customer", and pieces addressed "Jane Doe or Current Resident" (DMM 602.3.4). A "Current Resident" piece is "delivered as addressed and is not forwarded" (DMM 602.3.1.3), so the household living there today gets it whether or not Jane Doe moved.
Householding: one piece per home
A voter file lists people. Three registered voters at one address means three rows, and without householding, three postcards in one mailbox.
Householding merges them into one piece for the home. It saves print and postage on every duplicate, and the household gets one clean piece. For a campaign, decide first whether you want that: a letter to each voter by name is a different mailing from one card per home, and both are reasonable.
Exact duplicates are the other half. Lists merged from two sources, or a customer who signed up twice, leave the same address in the file twice. Merge/purge removes those.
What cleanup does to your count
Cleanup usually shrinks a list, and you pay postage only on what is left. Our pricing page works through an example, and the arithmetic looks like this:
- Your list has 10,000 names.
- After address checking, mover updates and duplicate removal, 9,600 are mailable, so 400 never print or mail.
- You are in our 10,000 tier: $2,800 for print and mail prep.
- Postage on 9,600 pieces at 29¢ to 40¢ each: $2,784 to $3,840.
- The 400 removed addresses would have cost $116 to $160 in postage for pieces that went to the wrong place or a second time to the same home.
How much any list shrinks depends on the list. That example is an illustration; we tell you your own mailable count before anything prints.
What our mailing service does on every list
When you send us a list for voter list mail, our mailing service runs it through CASS address standardization, NCOA mover updates and duplicate removal, with one piece per household. Then it presorts the mailing, inkjet-addresses each postcard and takes it to the post office as USPS Marketing Mail. Postage is billed at the actual rate after presort, usually 29¢–40¢ per piece. Cleaning one list is part of the price. If you have several lists to merge, tell us when you ask for a quote.
What to send us
- A spreadsheet. Excel or CSV works best.
- One person or home per row.
- Separate columns for first name, last name, street address, apartment or unit, city, state and ZIP.
- Your voter ID column, if it is a voter file. It lets us match the list against a later pull without guesswork.
- A note on householding. One piece per home, or one per person.
For a campaign, you can skip the spreadsheet: we can request the official voter list from your county elections office for you. For where lists come from and what they cost, see mailing lists explained.
Or let us do it
You can clean a list yourself with CASS-certified software and an NCOA service. If you would rather hand it off, send us the file and we will clean it, address it, presort it and mail it, and confirm your mailable count and postage first. See voter list mail, or ask us a question.
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