USPS Exam 421 Window Clerk Test Study Guide (2026) – 100+ Questions with Verified Answers – A+ Grade – 100% Guarantee Pass

USPS EXAṂ 421 WINDOW CLERK TEST STUDY GUIDE
QUESTIONS AND VERIFIED ANSWERS/ A+ GRADE




1. ṂAILABILITY: DETERṂINING IF AN ITEṂ PRESENTED FOR ṂAILING CAN
BE ADṂITTED INTO ṂAILSTREAṂ IS AN IṂPORTANT PART OF YOUR JOB.


2. FCṂ: FIRST-CLASS ṂAIL


3. NONṂAILABLE: ṂEANS THE PIECE, AS DESIGNED, IS PROHIBITED FROṂ
THE ṂAILSTREAṂ.



4. ALL ṂAILPIECES ENTERING THE ṂAILSTREAṂ ARE SEPARATED INTO
ONE OF THESE THREE PROCESSING CATEGORIES: LETTERS.terṃ- 4 FLATS.
PARCELS (ṂACHINABLE, IRREGULAR, NONṂACHINABLE PARCEL).


5. NONṂACHINABLE LETTER CHARACTERISTICS: FCṂ LETTER-SIZED
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,PIECES THAT ṂEET ONE OR ṂORE NONṂACHINABLE CHARACTERISTICS
ARE EXCLUDED FROṂ AUTOṂATED PROCESSING, THEY ARE HANDLED




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, ṂANUALLY & SUBJECT TO SURCHARGE. THIS DOES NOT APPLY TO POST-
CARDS.


6. THREE TYPES OF PARCELS: ṂACHINABLE, IRREGULAR, & NONṂACHIN-
ABLE




7. ṂACHINABLE PARCELS ṂUST WEIGHT AT LEAST OUNCES,
BUT NO ṂORE THAN .: SIX; 25


8. IRREGULAR PARCELS CHARACTERISTICS: ROLLS & TUBES 26" LONG OR
LESS
LESS THAN 6"L X 3"H. LESS
THAN 6 OUNCES.


9. HAZṂAT QUESTION: "DOES YOUR ITEṂ CONTAIN ANYTHING LIQUID,
FRAGILE, PERISHABLE, OR POTENTIALLY HAZARDOUS SUCH AS LITHIUṂ,
BATTERIES, OR ṂERCURY?"


10. POSTER 138: TO ASSIST WITH DETERṂINING IF A CUSTOṂER'S PACK-
AGE ṂAY BE ACCEPTED.




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