USPS Guide

This guide will teach you what makes USPS different from other carriers.

The goal of this guide is to detail the best and cheapest ways to use USPS shipping and USPS international. From the best ways to offer returns to the United States Postal Service's competitive pricing, we will walk you through predefined parcels, service levels, labels structures, and pick-up guidelines.

USPS has multiple service levels to support your business' every need. Naturally, the price of shipping parcels increases as the delivery time decreases. EasyPost supports all of USPS' functionality, along with the full functionality of 130 other carriers.

If you haven't shipped your first label with EasyPost, we recommend you check out our Getting Started Guide.

USPS Pricing

There are three USPS pricing tiers: Retail Rates, Commercial Base Pricing (CBP), and Commercial Plus Pricing (CPP).

EasyPost offers the lowest of the three tiers for all of our customers. Just sign up and get started shipping with Commercial Plus Pricing.

EasyPost also supports Cubic Pricing. Cubic Pricing is based on the cubic feet of a parcel. Cubic feet can be calculated using the following equation: Length x Width x Height / 1728. Cubic Pricing allows EasyPost customers to save money on small high-weight packages.

Service Levels

USPS has eleven service levels supported by EasyPost. Service levels have to do with both the speed and type of shipments. Each service level is detailed below. For reference, Girth is 2 times (Width + Height).

Service	Transit Time	Max Dimensions	Max Weight
First Class (Letters and Flats)	1-3 days	22" x 18" x 15" (55 cm x 45 cm x 38 cm)	13 oz (368 g)
First Class Package Service	1-3 days	22" x 18" x 15" (55 cm x 45 cm x 38 cm)	15.99 oz (453 g)
Priority	2-3 days	Combined Length and Girth < 108" (274 cm)	70 lbs (31 kg)
Express	1-2 days	Combined Length and Girth < 108" (274 cm)	70 lbs (31 kg)
Parcel Select	2-8 business days	Combined Length and Girth < 130" (330 cm)	70 lbs (31 kg)
Library Mail	2-8 business days	Combined Length and Girth < 108" (274 cm)	70 lbs (31 kg)
Media Mail	2-8 business days	Combined Length and Girth < 108" (274 cm)	70 lbs (31 kg)
First Class Package International	7-21 days	Combined Length and Girth < 108" (274 cm)	64 oz (1814 g)
Priority Mail International	6-10 business days	Combined Length and Girth < 108" (274 cm)	70 lbs (31 kg)
Express Mail International	3-5 business days	Combined Length and Girth < 108" (274 cm)	70 lbs (31 kg)

Predefined Parcels

USPS has nineteen predefined parcels supported by EasyPost, detailed below. Predefined parcels are an easy way to classify and therefore price a package. With the EasyPost API, pick a predefined parcel that qualifies for your shipment (and sometimes add the weight) in your request and request rates. See sample request in our predefined parcel documentation.

Predefined Package Name	Dimensions	Weight
Card	Min: 3 ½" x 5 ½" Max: 4 ¼" x 6"	Must be a flat surface
Letter	Min: 3 ½" x 5 ½" Max: 6 ⅛" x 11 ½"	Maximum weight is 3.5 oz.
Flat	Min: 6 ⅛" x 11 ½" Max: 12" x 15"	Maximum weight of 13 oz.
Parcel	Maximum size is 108" in combined length and girth (distance around the thickest part). First-Class™ packages cannot exceed 22" x 18" x 15".	Contents for Priority Mail Express, Priority Mail, or Media Mail® must weigh less than 70 lbs. First-Class™ packages must weigh less than 16 oz.
LargeParcel ^[1][3]	Maximum size is 130" in combined length and girth (distance around the thickest part).	Contents must weigh less than 70 lbs.
IrregularParcel ^[1][2]	Rolls and tubes up to 26" long. This predefined parcel includes unwrapped, paper-wrapped, or sleeve-wrapped articles that are not letter-size or flat-size (e.g., catalogs, directories). Articles enclosed in envelopes that are not letter-size, flat-size, or machinable parcels.	Contents must weigh less than 16 oz.
FlatRateEnvelope	12 ½" x 9 ½"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
FlatRateLegalEnvelope	15" x 9 ½"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
FlatRatePaddedEnvelope	12 ½" x 9 ½"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
FlatRateGiftCardEnvelope	10" x 7"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
FlatRateWindowEnvelope	10" x 5"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
FlatRateCardboardEnvelope	12 ½" x 9 ½"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
SmallFlatRateEnvelope	12 ½" x 9 ½"	Contents must weigh less than 70 lbs. International Weight limit: 4 lbs.
SmallFlatRateBox	8 ⅝" x 5 ⅜" x 1 ⅝"	Contents must weigh less than 70 lbs.
MediumFlatRateBox	11" x 8 ½" x 5 ½"	Contents must weigh less than 70 lbs.
LargeFlatRateBox	12" x 12" x 5 ½"	Contents must weigh less than 70 lbs.
RegionalRateBoxA ^[1]	Option 1: 10 ⅛" x 7 ⅛" x 5" Option 2: 16 ⅙" x 11 ⅙" x 2 ½"	Contents must weigh less than 15 lbs.
RegionalRateBoxB ^[1]	Option 1: 12 ¼" x 10 ½" x 5 ½" Option 2: 16 ¼" x 14 ½" x 3"	Contents must weigh less than 20 lbs.
LargeFlatRateBoardGameBox	23-11/16" x 11 ¾" x 3" – Inside 24-1/16" x 11 ⅞" x 3 ⅛" – Outside	Contents must weigh less than 70 lbs.

^[1] Not available for international shipments.
^[2] Only used with Parcel Select Lightweight.
^[3] Marks package for Balloon Price.

USPS Labels

EasyPost supports both domestic and international USPS labels in the following format: PNG, PDF, ZPL, EPL2, and ASCII. Request or convert your file type of your labels using our Label API. Below are two test PNG Labels, one is an international label (left) and the other is a domestic label (right):

USPS Pickups

USPS will pick up your package for free if you have one of following package types out for shipment:

Express Mail
Priority Mail
Returned Merchandise
International
First Class Package Service

Requests must be received by 2:00 AM CST in order to be picked up that day. After 2:00 AM CST, the USPS will come and pick up your packages during the next business day. Packages must be properly sealed and ready for shipment.