USPS package tracking, and the API behind it.
Domestic and international mail, including the USPS leg of eCommerce labels from other shippers. One free lookup a day, no sign-up.
Also known as United States Postal Service, Priority Mail, Ground Advantage.
USPS tracking numbers
We recognize these formats from the number alone. For anything else from USPS, add ?carrier=usps.
- Domestic barcode
- 92–95 + 18–24 digits, optionally led by 420 + ZIP
- International (S10)
- 2 letters + 9 digits + US
- Example (format only)
- 9400111899223197428490
- Category
- Major carriers
- API carrier code
- usps
USPS tracking API quickstart
One request per number, or up to 100 at once with ?numbers=a,b,c. Your agents can use the same data over MCP.
REST
curl "https://api.lastscanned.com/v1/track/9400111899223197428490?carrier=usps"Claude Code
claude mcp add --transport http lastscanned https://mcp.lastscanned.comThen ask
> Where is my USPS package 9400111899223197428490? When will it arrive?
USPS tracking FAQ
- How do I track a USPS package?
- Paste the tracking number into the lookup on this page. We read USPS's own tracking data and show every scan, the current status and the delivery details. Anyone can do one lookup a day without signing up.
- Is there a USPS tracking API?
- Yes. GET https://api.lastscanned.com/v1/track/:number?carrier=usps returns USPS tracking as JSON, in the same shape as every other carrier lastscanned covers. Sign up for a free key with 5 lookups a day, or Pro for $4.99 a month with 1,000 numbers.
- What does a USPS tracking number look like?
- Domestic barcode: 92–95 + 18–24 digits, optionally led by 420 + ZIP; International (S10): 2 letters + 9 digits + US. For example 9400111899223197428490. lastscanned recognizes these formats on its own, so ?carrier=usps is optional for them.
- Does this work for United States Postal Service and Priority Mail and Ground Advantage numbers?
- Yes. They are tracked through USPS and come back as carrier "usps".
- Can an AI agent track USPS packages?
- Yes. Add lastscanned as an MCP server (https://mcp.lastscanned.com) in Claude, ChatGPT, Cursor or VS Code and ask it where a USPS parcel is.
Other carriers
Major carriers
Regional US last mile
Tracking pages are for people. This is for your code.
Every carrier shows a parcel differently. lastscanned reads them all and answers in one shape, so your app, your spreadsheet or your agent handles any carrier the same way.
| Carrier website | lastscanned API | |
|---|---|---|
| Carriers | One carrier per site | 18 carriers behind one endpoint |
| Response | A web page to read | The same JSON for every carrier |
| Volume | One number at a time | Up to 100 numbers per request |
| Agents | Copy and paste | MCP server for Claude, ChatGPT and Cursor |
| Automation | Check back by hand | Poll from your own code or workflow |
Free: 5 numbers a day with a key. Pro: $4.99 a month for 1,000 numbers, then $0.015 each.