Effective April 28, 2005, Canada Post has advised the USPS that there is now only one addressing standard for Canada (previously there had been two formats).
The last line of the address must show only the country name, written in full and in capital letters.
There must be two spaces between the province abbreviation and the postal code. Below is the an acceptable example:
MS JANE DOE
1010 CLEAR STREET
OTTAWA ON K1A 0B1
CANADA
Mail services will be returning to departments Canadian bound mail that does not follow this format.
https://www.ithaca.edu/intercom/article.php/20050509115615817