CASS Cheat Sheet 2026

The 30 highest-yield CASS facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the role of the NCOA licensee in the NCOA process? → They are USPS-licensed vendors authorized to run mailer lists against the COA file
2. USPS charges a Move Update non-compliance surcharge on which class of mail? → Both First-Class Mail and Marketing Mail
3. Which USPS publication defines the technical specifications for the Delivery Point Barcode? → Domestic Mail Manual (DMM) Section 708
4. In the context of CASS certification, what is the most important consideration when implementing presort & mail preparation? → Ensuring alignment with established standards, stakeholder needs, and best practices
5. How does CASS certification treat a Secondary Address Unit (SAU) that exists in the database but was not provided in the input address? → It flags the address as requiring secondary information
6. When comparing two candidate address matches in CASS processing, which component mismatch is most likely to cause a match to be rejected? → A difference in street name with matching primary number
7. During a USPS audit of automation rate claims, which documentation must a mailer be prepared to provide? → PS Form 3553 (CASS Summary Report) along with address correction and match records
8. Under CASS certification rules, what must a mailer do when an address database contains records for US territories like Guam or the U.S. Virgin Islands? → Process them through the standard CASS cycle as domestic addresses
9. What happens when a mailer submits a list to an NCOA licensee and a match is found with a 'temporary' move flag? → The mailer is notified but no address change is applied
10. What is the maximum number of address lines recommended by UPU S42 for an international postal address? → 6 lines
11. How often does the USPS require CASS-certified software to be re-certified to maintain its certification status? → Every cycle (approximately every two years)
12. What does a DPV confirmation indicator of 'Y' signify? → Both the primary and secondary address numbers are confirmed as valid delivery points
13. When a CASS-certified system assigns a DPV confirmation indicator of 'S,' it means: → The primary number is valid but the secondary number is missing or invalid
14. What is the role of the USPS Address Management System (AMS) in CASS processing? → It provides the reference database of all known USPS deliverable addresses
15. A mailer's CASS Form 3553 shows a 90% ZIP+4 match rate. What is the minimum match rate required by USPS to qualify for 5-digit basic automation rates? → 95%
16. When standardizing a directional in an address such as '123 N Main St', what does USPS Publication 28 call the element 'N'? → Predirectional
17. In POSTNET coding, each digit is represented by a combination of how many tall and short bars? → 2 tall, 3 short
18. When preparing automation-compatible First-Class Mail, what is the maximum height allowed for a letter-size piece? → 6.125 inches
19. Which ZIP+4 footnote is returned when an address matches only at the 5-digit ZIP Code level and no ZIP+4 code can be assigned? → A1
20. A CASS system flags an address as 'DPV Vacant'. What action should a mailer typically take with this record? → Suppress the record from the mailing to avoid waste
21. Which address deficiency most commonly causes addresses to fail automation rate qualification during CASS processing? → Address cannot be confirmed as an actual USPS delivery point (DPV failure)
22. Why is annual certification required? → Maintain postal compliance
23. A dedup match code of 'H' in most CASS-certified systems typically indicates: → A household-level match with different given names
24. Which address components are primarily used to determine and assign a ZIP+4 code suffix? → Street name, primary number, and secondary number
25. What is the maximum acceptable skew angle for a POSTNET barcode printed on a mail piece per USPS standards? → 5 degrees
26. What is the benefit of complying with USPS addressing standards? → Better deliverability and discounts
27. An address listed as '100 N. Oak Street Northwest' should be standardized to which USPS format? → 100 N Oak St NW
28. What is the consequence of using uncertified software? → Mail rejection or lost discounts
29. In merge-purge terminology, a 'dupe' that is retained while all other copies are suppressed is called the: → Survivor record
30. How are ambiguous addresses handled? → Use extra data to clarify