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Systems at Work


These bars represent a ZIP Code.

Once numbers—ZIP Codes—began to represent addresses, barcodes representing numbers was the next step. Barcodes are easily read by machines all along the path of a letter or parcel. From the start, they helped mail reach its destination faster and more accurately. Today, they help generate information for senders and recipients as mail moves across the country.

How do bars represent ZIP Codes?
The USPS began using barcodes in 1982. The bars represented the 5 digits of the ZIP Code, and helped automate mail sorting—the machines read the stripes instead of the numbers.

What’s in a barcode besides the ZIP Code?
Over the years, the USPS has used 5, 6, 9, and now 11-digit barcodes to steadily increase the speed and accuracy of mail delivery. The extra bars include “carrier sort” level coding that sorts the mail to the order it’s delivered in.

Think you can decipher a barcode? Try this:

Decode the Barcode »

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