Quick Service Guide 230b
First-Class Mail is required for personal correspondence, handwritten or typewritten material, and bills or statements of account. It also may be used for any mailable item including advertisements and lightweight merchandise.
Eligibility Standards (233.4.0)
Mailings of 500 or more addressed pieces, sorted and marked as described below. All pieces must be machinable; see 201.1.0. Pieces mailed at card prices and pieces mailed at letter prices must meet separate 500-piece minimums.
Addresses on all pieces must be updated within 95 days before mailing through a USPS-approved address update method (e.g., ACS, NCOALink, or the appropriate ancillary service endorsement except Forwarding Service Requested. under 507.1.5). For an overview of the Move Update standards, see Quick Service Guide 230a.
When preparing full trays, mailers must fill all possible 2-foot trays first; if there is mail remaining for the presort destination, mailers must use a combination of 1-foot and 2-foot trays that result in the fewest total number of trays for that presort level.