May 18


Mailing Guidelines 101

VariableSizing Guidelines:

  • Mail piece min size: 5” wide x 3 1/2” high x 0.007” thick
  • Postcard max size: 6” wide x 4 1/4” high x 0.016” thick Letter max size: 11 1/2” wide x 6 1/8” high x 0.25” thick
  • Flat min size: 6” wide x 5” high x 0.009” thick
  • Flat max size: 12” wide x 15” high x 0.75” thick

Note: A mail piece must exceed at least one of the maximum letter dimensions to be categorized as a flat. If the mail piece does not exceed the letter requirements, it must be tabbed and mailed as a letter.


Postage Guidelines:

A display of postage paid must be applied to ALL pieces of mail. Options include:

  • Permits: The most effective way to apply postage. An indicia bearing the permit number of your company or mail house is imprinted on your mail piece either at the time of printing or mailing.
  • Stamps: Not just for First Class mail, there is a stamp for each permit type also. Letters with stamps have a higher rate of return than mail with indicias.
  • Meter: Used for First Class mail only. Postage amount prints onto each mail piece.


Mailing Lists:

The format of the mailing list is critical to ensure accurate delivery of the piece. Below is a sample of a good and bad mailing list:

  • Acceptable: (First Name) (Last Name) (Address 1) (Address 2) (City) (State) (Zip)
  • Unacceptable: (First Name) (Last Name) (Address, City, State, Zip)


{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}