Stamps.com (USPS) Carrier Guide
Stamps.com with ShipEngine provides access to USPS domestic and international shipping services for packages originating in the United States.
This guide provides developers an overview of shipping services that Stamps.com offers and the service codes that you will use to create these shipments.
Connect Your Account
ShipEngine API allows you to connect your Stamps.com account programmatically without logging in to the ShipEngine API dashboard. This is useful if you have wrapped a custom UI around the ShipEngine API toolset and want to add or disconnect existing carrier accounts without exposing your end users to the API dashboard.
These APIs can be used in parallel with the ShipEngine Partner APIs to programmatically create new ShipEngine users, and then connect existing Stamps.com accounts all via the API without logging into a dashboard. Together these APIs empower you to completely white-label the ShipEngine experience for your end users.
Continue below for instructions on how to programatically connect Stamps.com using the ShipEngine API.
For instructions on connecting a Stamps.com via the ShipEngine dashboard, go to our Stamps.com help article.
Stamps.com Account Information Model
Property | Description |
---|---|
username | string, required |
password | string, required |
Example POST Call
POST /v1/connections/carriers/stamps_com
Example Response
Stamps.com Service Details
Stamps.com includes both USPS domestic and international services. Additionally, you can also access GlobalPost international services with a Stamps.com account.
USPS Domestic Services
Service | Transit Time | Maximum Dimensions (LxWxH) | Max Weight | Service Code |
---|---|---|---|---|
USPS Ground Advantage* | 2-5 days | 22" x 18" x 15" | 70 lbs | usps_ground_advantage |
USPS Priority Mail | 1-3 days | varies by package type | 70 lbs | usps_priority_mail |
USPS Priority Mail Express | 1-2 days | L x 2xW x H cannot exceed 108" | 70 lbs | usps_priority_mail_express |
Media Mail | 2-9 days | L x 2xW x H cannot exceed 108" | 70 lbs | usps_media_mail |
*In 2023, USPS Ground Advantage replaced both USPS First Class Package and Parcel Select Ground services.
USPS International Services
Service | Transit Time | Maximum Dimensions | Max Weight | Service Code |
---|---|---|---|---|
USPS First Class Mail Intl | 7-21 days | L x 2xW x H cannot exceed 136" | 64 oz | usps_first_class_mail_international |
USPS Priority Mail Intl | 6-10 days | L x 2xW x H cannot exceed 108" | 70 lbs | usps_priority_mail_international |
USPS Priority Mail Express Intl | 3-5 days | L x 2xW x H cannot exceed 108" | 70 lbs | usps_priority_mail_express_international |
GlobalPost Services
For all GlobalPost services, transit time will vary depending on the destination country.
Service | Max Weight | Service Code |
---|---|---|
GlobalPost Economy Intl | 4.4 lbs | globalpost_economy |
GlobalPost Standard Intl | 70 lbs | globalpost_priority |
GlobalPost Plus | 66 lbs | gp_plus |
GlobalPost SmartSaver Economy Intl | 4.4 lbs | globalpost_economy_smart_saver |
GlobalPost SmartSaver Standard Intl | 70 lbs | globalpost_priority_smart_saver |
GlobalPost Plus SmartSaver | 66 lbs | globalpost_plus |
USPS Package Types
Package Name | API Code | Package Details |
---|---|---|
Medium Flat Rate Box | medium_flat_rate_box | Domestic and international |
Flat Rate Envelope | flat_rate_envelope | Domestic and international |
Small Flat Rate Box | small_flat_rate_box | Domestic and international |
Large Flat Rate Box | large_flat_rate_box | Domestic and international |
Flat Rate Padded Envelope | flat_rate_padded_envelope | Domestic and international |
Flat Rate Legal Envelope | flat_rate_legal_envelope | Domestic and international |
Example Label
Return Services
Return services are supported for USPS domestic shipments.
Adding Shipment Insurance
Stamps.com supports adding insurance to your shipments. Review the Parcel Insurance page for details on adding shipment insurance with ShipEngine.
USPS Advanced Options
Advanced Options are a shipment property used to communicate carrier add-ons used, such as "Saturday Delivery" or "Dangerouse Goods". Carrier Options are available dynamically at the List Carriers endpoint.
Option | Name | Default Value | Description |
---|---|---|---|
Non Machinable | non_machinable | false | Indicates that the package cannot be processed through USPS sorting machines. |
Dangerous Goods | dangerous_goods | false | Indicates this shipment contains dangerous goods |
Additional Carrier Details
- Signature and Adult Signature confirmation types not supported for international shipments.
- Label messages are supported for domestic shipments only.
- Voiding labels is supported, but must be done within 28 days of label creation.
- USPS pickups can only be scheduled for one day in advance. For example, if you schedule a pickup on the 5th for the 7th, the pickup date scheduled by Stamps.com will be the 6th.
- If you plan to create a USPS SCAN form, you must manifest your day's shipments by 9pm local time.
- All international shipments using USPS First-Class Mail Int'l, Priority Mail Int'l, or Priority Express Int'l services will use Global Advantage Program labels by default.
Paperless Services
USPS supports paperless labels with their services. This means you can generate a QR code for your customer and they can take that QR code to be scanned at participating USPS locations, who will then print the label for them.
Review our paperless labels page for details on how to generate a QR code instead of a printable label. Currently this supports the qr_code
value for the display_scheme
property.
Example QR Code
Customer Communications
Using paperless labels might be a new experience for your customers. The USPS suggests sending out an email with the QR code label to help educate your customer on what they need to do to ship their package.
The email containing the QR Code should also include instructions on how to find participating USPS Post Offices by visiting https://tools.usps.com/find-location.htm?locationType=po&serviceType=lbroretail&address=18702, where the value of the address parameter is customer's ZIP Code (such as 18702 in this example). The USPS Retail Associate at that location's Retail Counter will scan the QR Code and print the shipping label, affix it to the package, and provide a receipt.
If the customer has access to a printer, they may choose instead to print the label directly at https://tools.usps.com/label-broker.htm?LabelID=XYZZYPJK&zip=18702, where XYZZYPJK is the Label ID returned by ShipEngine, and 18702 is the ship_from
postal_code
.
You are now ready to create shipments using Stamps.com via ShipEngine!