RocketShipIt for USPS® Shippers

"I was planning on working on this project until next monday but it's already just about wrapped up thanks to RocketShipIt" -- Wyatt G -

Why RocketShipIt?

Features and Benefits

  • Implement an easy to use API into your existing website in minutes
  • Process shipments faster than ever
  • Save tracking numbers to your web site to provide better customer service
  • Automatically upload shipping charges to your accounting software
  • RocketShipit is capable of producing thermal, laser, or inkjet labels
  • Same API across multiple carriers, RocketShipIt decreases switching costs
Usps logo

What does it do?

Automatically generate shipping labels

Print postage paid labels with RocketShipIt + Postage can be hidden so customers don't see it. Simply supply the address, weight, and any additional services and RocketShipIt does the rest.

Save money, actual rates

RocketShipIt gives you actual rates direct from the carrier. RocketShipIt uses the same backend API that the carriers use on their own site to rate shipments. Rate based on a daily pickup, customer counter, and more. Avaliable rate types include: List Rates, Discounted Rates (based on your account number), and Suggested Retail Rates.

Find out transit time before you ship New!

Ever wonder how Amazon can tell you when your package will arive before you checkout? RocketShipIt uses the carrier's Time in Transit API to calculate the time it will take for packages to reach your customers based on their distance from your shipping facility.

Free updates for life

As with all RocketShipIt products you recieve free updates for life. If a carrier adds a new feature, changes their APIs, or new carriers are added you get it all for free.

Easily track and display package history

Increase exposure by providing your customers with real time package tracking on your own site. Track by shipment id, reference number, invoice number, RMA number, and more.

Print Postage Paid Labels

Print postage paid labels with RocketShipIt + Postage can be hidden so customers don't see it.

Create a Shipment and Label

Here is an example JSON request which creates a shipment and label with RocketShipIt's USPS API.

  "carrier": "Stamps",
  "action": "SubmitShipment",
  "params": {
    "username": "YOUR_USERNAME",
    "password": "YOUR_PASSWORD",
    "packages": [
        "weight": 5,
        "length": 6,
        "width": 7,
        "height": 8,
        "packaging_type": "Package"
    "shipper": "RocketShipIt",
    "ship_addr1": "123 Main St",
    "ship_city": "Whitehall",
    "ship_state": "MT",
    "ship_code": "59759",
    "ship_phone": "1231231234",
    "to_name": "John Doe",
    "to_addr1": "123 Dont Ship st",
    "to_state": "MT",
    "to_city": "Whitehall",
    "to_code": "59759",
    "service": "US-PM",
    "reference_value": "123asdf"

Example Label

USPS GIF Shipping Label Generated from API

Purchase RocketShipIt™ for USPS

RocketShipIt™ for USPS comes with a complete API interface to the USPS Web Services and online support to help you get your code integrated as quickly as possible.

You get:

RocketShipIt™ for USPS powered by

In order to create postage paid labels you will need a subscription to

Discounted USPS Rates

When you purchase RocketShipit for USPS and sign up for a account through this link your account will automatically have access to discounted rates. The discounts will allow you to save up to 46% on USPS Priority Mail and Priority Mail Express shipments.

If you're already a RocketShipIt customer and have an existing account you will need to email [email protected] and request the RocketShipIt-IntuiShip rates.

Frequently Asked Questions

Does the RocketShipIt script connect to USPS directly?


How fast are response times for fetching rates and label generation?

Since RocketShipIt communicates directly from your server to the carrier you achieve the best possible response times. You can usually expect requests to be returned in less than one second for most carriers depending on your network connection and location.

Can RocketShipIt be used in commercial applications?


Does RocketShipIt work with Zencart, OScommerce, Magento, Paypal, or Cart X?

The short answer is yes. Technically, RocketShipIt will work with anything that uses PHP 5+ and has the cURL extension installed. All you need to do is pass in the address and weight information and RocketShipIt will do the rest.

Can I print thermal labels with RocketShipIt™ for USPS?


What formats do labels come in?

ZPL, EPL, EPLII, and GIF labels. ZPL/EPL are the print codes (in base64) required for thermal printing.

What can I do with the labels after I get them?

The labels come back in base64 format, which basically means they are a string. They can be embedded in an HTML page for viewing/printing, stored in a database, sent to a thermal printer, inserted into a PDF, saved as a GIF file, or emailed off. RocketShipIt doesn't impose any limits to what you can do with them.

Can I see a sample GIF label?


Does RocketShipIt calculate dimensional weight?


Does RocketShipIt work for International shipments?

RocketShipIt works great internationally. We have RocketShipIt customers shipping to and from just about every country in the world. We even support paperless customs and international document generation for many countries.

Can I create shipments with multiple packages?


Can I create return labels and email them to my customers?

Yes, you can even provide the customer's email address and have USPS email them on your behalf.

What are negotiated rates?

Negotiated rates include the retail rate minus the discount you get for being a USPS volume shipper. This is the rate you recieve from USPS.

Are there any limitations in RocketShipIt™ for USPS?

RocketShipIt™ for USPS is a complete API for USPS. RocketShipIt can do anything that the carrier allows; however, if you find a feature missing in RocketShipIt that you would like added we can usually accommodate such requests in very short time.

Are there any discounts for purchasing RocketShipIt for multiple carriers?

You can get support for all carriers for one low price see pricing.

Can RocketShipIt handle my volume?

Since RocketShipIt connects to USPS directly you are utilizing the power of their servers. Currently RocketShipIt does over ten thousand shipments per day.

Does RocketShipIt handle end of day reports?

RocketShipIt creates the labels directly through the USPS API. USPS is notified immediately when a label is printed so there is no need for an end of day report.

You'll love us, Money Back Guarantee

We guarantee you'll love us, if you are not totally satisfied we'll give you a 100% refund.

Try it Free

* 100% money back guarantee.

  • No per-label or additional fees
  • Free online support from a shipping expert
  • Support for UPS, FedEx, USPS, DHL, CanadaPost, and more
  • Print server for printing thermal labels from a web-browser
  • Free updates