Disclaimer: This tool has no warrenty and I assume no liability for your mail loss, for example, a lost tax return to IRS

This is the tax season again. I hate go to the post office to just get a certified label to make sure my tax return is delivered. I also hate to pay $4.15 for a certified mail. I know there is a way to track a plain mail with a barcode See my other post here, but it is not easy to use. Thus, I made a tool.

How to use it

  1. Visit https://slu.t.cuitian1.com/envelope
  2. Type in the recipient address and your return address, click generate
  3. Remember your serial number and the recipient zipcode
  4. Print the address and the barcode (The most important) on to the envelope
  5. Tracking using the bottom part of the website
  6. Star the Github project if you like it
  7. In case of the website down, you can go to Github repo to deploy your own.

A sample tracking Above is a sample tracking record that can be obtained from the website.

Why it works

As a lot of people know, USPS has a handy tool called informed delivery. How it works is basically USPS scans the barcode on the mail, which can uniquely identify an address.

letter with a barcode

letter with a barcode

It turns out that you can generate your own barcode and put it on the mail, and USPS can help you track it! This functionality is called Informed Visibility, which uses the same barcode.

I create this tool with Informed Visibility, basically generate a barcode for you to track.


USPS doesn’t scan the barcode during every hop of the mail. Thus, the tracking information is not as detail as a certified mail. Specifically, for a first class letter, the carrier didn’t scan individually of them during delivery. As a result, the last hop (i.e. delivery) is not reliable. Sometimes, my tool can capture a logical delivery event, which means the postman entered the zipcode of the recipient, but not always. However, the tracking information can give me enough confidence that the mail is delivered.