Here are the service levels for three of our most commonly-used carriers:
First-Class Package/Mail Parcel (max 15.9 oz)
First Class Package International Service
Priority Mail Express
Priority Mail Express International
Priority Mail International
Parcel Select Ground (also known as Parcel Select - Nonpresort)
Note: The USPS technology (ePostage) used by Shippo does not currently support the use of Media Mail, Library Mail, First Class Flats, or Letter Rates.
Home Delivery (same service as Ground, but for deliveries to residential addresses)
Ground (same service as Home Delivery, but for deliveries to business addresses)
3 Day Freight
2 Day A.M.
Express Early A.M.
Mail Innovations Domestic
Next Day Air
Next Day Air Early A.M.
Next Day Air Saver
Second Day Air
Second Day Air A.M.
World Wide Saver
Worldwide Express Plus