I am never too sure where the Buzon Number should be in my address.

Should it be at the beginning or the end or somewhere in the middle.

fwiw I was informed my real (ie the house) address should not be used but I object to that so I put both - the bit that matters of the 'real' one in brackets above, then the Buzon bold & capitals, & it doesn't matter how many times I tell people the right form I was given by the ayuntamiento - ie

nameoflocation Buzon 9
cp 999999 Puebloname
provincia de name

people still muddle it up, and providing the Buzon details are there somewhere, it arrives! (thus far!)

When we asked we were told that it had to be the following format;

<street name> <street number>
<box number>
<postal code> <town>
<state>
<country>

Thats the format the local correros told us to change to when they changed all the addresses while we lived in Orihuela Costa.

That's presumably for town buzones; we in't campo possibly have a different format: mine in similar style would be

Name of Buzon Location -- Buzon Number (on the same line)
CP of pueblo Pueblo (on the same line)
Province