The goal of this guide is to detail the best and cheapest ways to use USPS. We will walk you through the United States Postal Service's competitive pricing, 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 increase as the delivery time decreases. EasyPost supports all of USPS' functionality, along with the full functionality of 60+ 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:

ServiceTransit TimeCombined Length and Girth (L+2W+2H)Max Weight
First Class1-3 days108" (274 cm)13 oz (368 g)
Priority2-3 days108" (274 cm)70 lbs (31 kg)
Express1-2 days108" (274 cm)70 lbs (31 kg)
Parcel Select2-8 business days130" (330 cm)70 lbs (31 kg)
Library Mail2-8 business days108" (274 cm)70 lbs (31 kg)
Media Mail2-8 business days108" (274 cm)70 lbs (31 kg)
Standard Post2-8 business days130" (330 cm)70 lbs (31 kg)
Critical Mail2-8 business days108" (274 cm)13 oz (368 g)
First Class Package International7-21 days108" (274 cm)64 oz (1814 g)
Priority Mail International6-10 business days108" (274 cm)70 lbs (31 kg)
Express Mail International3-5 business days108" (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 NameDimensionsWeight
Card
  • Min: 3 1/2“ x 5 1/2"
  • Max: 4 1/4” x 6”
Must be a flat surface
Letter
  • Min: 3 1/2” x 5 1/2”
  • Max: 6 1/8” x 11 1/2”
Maximum weight is 3.5 oz.
Flat
  • Min: 6 1/8” x 11 1/2”
  • Max: 12 x 15”
Maximum weight of 13 oz.
ParcelMaximum size is 108" in combined length and girth (distance around the thickest part).Contents for Priority Mail Express, Priority Mail, or Media Mail® must weigh less than 70 lbs. First-Class™ packages must weigh less than 15.9 oz.
LargeParcelMaximum size is 130" in combined length and girth (distance around the thickest part).Contents must weigh less than 70 lbs.
IrregularParcel
  • Rolls and tubes up to 26 inches 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 70 lbs.
FlatRateEnvelope12-1/2" x 9-1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateLegalEnvelope15" x 9 1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRatePaddedEnvelope12 1/2" x 9-1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateGiftCardEnvelope10" x 7"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateWindowEnvelope10" x 5"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateCardboardEnvelope12 1/2" x 9-1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
SmallFlatRateEnvelope12 1/2" x 9 1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
SmallFlatRateBox8 5/8" x 5 3/8" x 1 5/8"Contents must weigh less than 70 lbs.
MediumFlatRateBox11 x 8 1/2 x 5 1/2Contents must weigh less than 70 lbs.
LargeFlatRateBox12 x 12 x 5 1/2Contents must weigh less than 70 lbs.
RegionalRateBoxA
  • Option 1: 10 1/8 x 7 1/8 x 5
  • Option 2: 16 1/6 x 11 1/6 x 2 1/2
Contents must weigh less than 15 lbs.
RegionalRateBoxB
  • Option 1: 12 1/4 x 10 1/2 x 5 1/2
  • Option 2: 16 1/4 x 14 1/2 x 3
Contents must weigh less than 20 lbs.
LargeFlatRateBoardGameBox
  • 23-11/16" x 11-3/4" x 3" – Inside
  • 24-1/16" x 11-7/8" x 3-1/8" – Outside
Contents must weigh less than 70 lbs.

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

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.