What is First-Class Mail used for?
First-Class Mail is for personal, private, or time-sensitive content, and for anything the rules require to go First-Class. Invoices, statements, checks, appointment reminders, lab results, and personal correspondence must go First-Class, not Marketing Mail. It is the fastest routine class and covers cards, letters (up to 3.5 ounces), and flats (up to 13 ounces). Parcels no longer travel as First-Class Mail; they ship as USPS Ground Advantage or Priority Mail. The price includes forwarding for up to 12 months and return of undeliverable pieces. See DMM 133.
What can and cannot go in USPS Marketing Mail?
USPS Marketing Mail (formerly Standard Mail) carries advertising, promotional, and solicitation content sent in bulk. It cannot contain personal correspondence, bills, statements, or anything required to go First-Class. Each piece must weigh less than 16 ounces, and it must be sent as a bulk mailing (see How many pieces do I need for presort pricing). Postage is lower than First-Class in exchange for slower, non-guaranteed delivery. Forwarding and return are not included unless an ancillary service endorsement is added and paid for. See DMM 243.
Who can use Nonprofit Marketing Mail prices?
Nonprofit Marketing Mail prices are available only to nonprofit organizations USPS has authorized, and only for their own mailings. They are reduced Marketing Mail prices with their own authorization and content eligibility rules. Plavidian prices nonprofit postage only from the explicit nonprofit rows in Notice 123, never by scaling commercial rates. See DMM 243 and 703.
Bound Printed Matter
Bound Printed Matter is for advertising, directories, or catalogs made of printed sheets bound together, generally heavier promotional print pieces. Weight and content limits apply. See DMM 263.
What qualifies for Media Mail?
Media Mail is for eligible media only (books, sound recordings, educational material), and it cannot contain advertising. It is low cost, slow, and subject to inspection, and it is rarely used for marketing mail. See DMM 273.
How do I choose a mail class?
For a typical mailing, decide in this order. If the content is personal, private, or required to go First-Class, use First-Class. If it is advertising sent in bulk and meets the minimum quantity, USPS Marketing Mail (or Nonprofit, if the mailer is authorized) is usually cheapest. To saturate a geographic area without a mailing list, use EDDM (see What is EDDM). For exact price comparisons, use the Postage Estimator, which prices from the imported Notice 123.