What label options are available for USPS?

This USPS label guide will walk you through label size and format options and other important USPS label notes.

USPS Label Sizes

Possible values for USPS label sizes (actual results may vary):

  1. "4x6" (default)
  2. "4x4"
  3. "8.5x11"
  4. "7x3" (available when predefined_package = "Letter" and when the "First" rate is purchased, otherwise default "4x6" sized label will be returned. See Predefined Packages.)
  5. "6x4" (available when predefined_package = "Card" OR "Letter" and when the "First" rate is purchased, otherwise default "4x6" sized label will be returned. See Predefined Packages.)
Note: ZPL format may not be supported for letter and card label sizes.

USPS Label Formats

Possible values for USPS label formats (actual results may vary):

  1. "PNG"
  2. "PDF"
  3. "ZPL"
  4. "EPL2"

USPS label custom text options

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

  1. print_custom_1
  2. print_custom_2
  3. print_custom_3
  4. invoice

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

USPS label custom text options
JSON Example
"options": {
  "print_custom_1": "printCustom1",
  "print_custom_2": "printCustom2",
  "print_custom_3": "printCustom3",
  "invoice_number": "INVOICE12345",
  "label_size": "4x6",
  "label_format": "PNG"
}
  
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