Postage for First-Class Package Service parcels must be paid with postage evidencing system postage or permit imprint as specified below. All pieces in a mailing must be paid with the same method unless otherwise authorized by Business Mailer Support (see 608.8.0 for address).
[1-17-16] All First-Class Package Service parcels may bear permit imprint postage under 604.5.0. All mail manifested using the Electronic Verification System (eVS) under 705.2.9 must be paid using a permit imprint. A permit imprint may be used for mailings of nonidentical-weight pieces only if authorized by Business Mailer Support.
[1-17-16] Each First-Class Package Service parcel bearing postage evidencing system indicia (IBI Meter or PC Postage) must bear the full numerical value of postage at the First-Class Package Service price for which it qualifies.