In order to encourage the definition of rules and methods permitting evaluation of the quality of service levels attained by all postal administrations, the Postal Operations Council approved in 2003 a common quality evaluation system developed by the UPU International Bureau, on the basis of resolution C20/1999 of the Beijing Congress.
This system is better known as "UPU certification of postal administrations in the quality management field".
Below is a comprehensive list of UPU-certified postal administrations and of certification documents: