USPS Label Options

This article will walk you through USPS shipping label size and formatting options available within EasyPost. You will see how to change the size and format of your USPS shipping label below.

• USPS label sizes
• USPS label formats
• USPS shipping label custom text options
• JSON example

USPS label sizes

 Possible values for USPS shipping label sizes (results will vary):

• 4x6 (default)
• 4x4
• 8.5x11
• 7x3 (this size should be available when using "predefined_package":"Letter" and when the "First" rate is purchased. See Predefined Packages).
• 6x4 (this size should be available when "predefined_package":"Card" OR "Letter" are used, and when the "First" rate is purchased. See our API documentation regarding Predefined Packages for more information).

Note: ZPL format may not be supported for letter and card label sizes.

USPS label formats

Possible values for USPS label formats (results will vary):

• "PNG"
• "PDF"
• "ZPL"
• "EPL2"

USPS shipping label custom text options

You can use the below options to print custom text on USPS labels. See our Shipment Options documentation for specifics.

• print_custom_1
• print_custom_2
• print_custom_3
• invoice_number

These values will appear beneath the address on the USPS label, as shown here:

JSON example

"options": {
  "print_custom_1": "printCustom1",
  "print_custom_2": "printCustom2",
  "print_custom_3": "printCustom3",
  "invoice_number": "INVOICE12345",
  "label_size": "4x6",
  "label_format": "PNG"
}