USPS Tracking API for Developers

Use C2W Package Tracking API to retrieve USPS shipment information through RapidAPI. The documented endpoint accepts a tracking number and returns JSON for your application. Webhooks are not supported.

How to request USPS tracking

Subscribe on RapidAPI and keep your credentials on your server.
Send your shipment’s tracking number as trackingNumber to GET /TrackingPackage.
Check the HTTP response before reading tracking fields. Use the API reference for headers and schema.

curl --get 'https://trackingpackage.p.rapidapi.com/TrackingPackage' \
  --data-urlencode 'trackingNumber=YOUR_TRACKING_NUMBER' \
  --header 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
  --header 'X-RapidAPI-Host: trackingpackage.p.rapidapi.com'

Add an Authorization header only if it was issued for your integration. This example uses a placeholder; it does not query a real shipment.

Illustrative response, not a live shipment

This synthetic subset illustrates documented field names. It is not a recorded USPS response or a guarantee that every shipment supplies these values.

{
  "TrackingNumber": "YOUR_TRACKING_NUMBER",
  "Carrier": "USPS",
  "Delivered": false,
  "Status": "In transit"
}

See authentication and error handling. Keep credentials server-side and treat network failures separately from shipment status.

Plan polling and cost before subscribing

Webhooks are not supported. Your application schedules requests and customer notifications. Results may be cached; a successful call does not imply a new carrier scan.

Example: 25 active shipments checked four times per day use 100 requests, before retries and manual refreshes. The Pro plan includes 150 requests/day at $9.99/month, leaving 50 requests of headroom. This is a workload example, not a recommended polling interval.

The free plan includes 5 requests/day for evaluation. Space requests within the rate limit and stop routine polling when your workflow is complete. Compare plans and request budgets; confirm applicable terms in RapidAPI.

Handle postal events without losing detail.

USPS shipment events can be useful to order-support teams even when a package has not yet been marked delivered. Preserve both the overall Status and the available TrackingDetails event history in your application.

Separate an empty result from a delivery exception

A failed HTTP request, an unavailable event history, and a carrier-reported delivery exception are different cases. Show an unavailable-data state for missing information rather than marking a parcel lost or delivered. Keep the original tracking number as text.

Plan a direct-USPS migration carefully

When replacing an existing USPS integration, confirm access for your shipment sources and compare real responses for your mail services. Do not assume access available through one account or integration transfers to another.

For USPS’s own API access information, see the USPS developer portal. For a provider shortlist, read our USPS API alternatives guide.

Fields to consider in your application

Integration considerations, not guaranteed field availability
Field	Application handling
`Status`	Present the latest human-readable state.
`TrackingDetails`	Render the available scan history, including its original event text.
`Delivered`	Check for an explicit delivered value; missing data is not delivery.

Available values depend on the shipment and carrier data. Empty strings, null values, and absent fields should not break your interface. These are schema notes, not a recorded USPS production response.

Before going live

Test delivered, in-transit, unavailable-data, and exception cases for your services. Establish your polling schedule, request headroom, and support process. Use our integration guide and request-budget examples.