§ 121.0 Market-dominant product service standards.
Current through Sep 25, 2026 · Read all of Part 121
Service standards in this part are contingent upon proper acceptance before the applicable day-zero Critical Entry Time (CET). Applying the service standards appearing in this part, effective service standards for combinations of 5-digit originating ZIP Codes and 5-digit destinating ZIP Codes can be found in a lookup table at www.usps.com.