Stamps have been used since the mid 1800s to send letters and there must be tens (if not hundreds) of thousands of stamp designs and denominations. How are they tracked?
In: 6
If I recall, stamps have uv ink printed on the backer paper showing the denomination. That ink is visible to the sorting machines which detect “sufficient postage” or “invalid/insufficient postage” and kick the letter out of the sorting machine for manual verification. Modern stamps can also have qr codes on them which are read for the denomination.
The UPU (Universal Postal Union), founded in 1874, requires that each country send samples of their stamps to be distributed to other countries.
When letters are collected from mailboxes, etc. the postal employee examines the stamp(s) and determines if postage has been paid. The vast majority of letters will have recent stamps and be familiar to the postal worker. I presume if there’s any question, it can be instead routed for further inspection.
Stamps have been used since the mid 1800s to send letters and there must be tens (if not hundreds) of thousands of stamp designs and denominations. How are they tracked?
In: 6
If I recall, stamps have uv ink printed on the backer paper showing the denomination. That ink is visible to the sorting machines which detect “sufficient postage” or “invalid/insufficient postage” and kick the letter out of the sorting machine for manual verification. Modern stamps can also have qr codes on them which are read for the denomination.
The UPU (Universal Postal Union), founded in 1874, requires that each country send samples of their stamps to be distributed to other countries.
When letters are collected from mailboxes, etc. the postal employee examines the stamp(s) and determines if postage has been paid. The vast majority of letters will have recent stamps and be familiar to the postal worker. I presume if there’s any question, it can be instead routed for further inspection.
Latest Answers