John (my cousin) & Jane (cousin-in-law)
When sending a letter and writing their names on the envelope, which is correct?
I would think #2 is correct because I don’t have to repeat the word “cousin” because they are both my cousins, but I don’t want Jane to feel like I don’t consider her a cousin because I didn’t write “Cousin Jane” so in that case should I just write Cousin John & Cousin Jane?
And it should be noted that "Cousin John" is only "cousin" to relatives, not the mailman or the people next door. It serves no purpose in more accurately addressing the letter.
Ultimately, the name on an envelope is intended for use by the postal service. For this reason, you should always write out the full names (and only the full names) of the addressees, so that misdelivered or incorrectly addressed mail has a higher chance of reaching the intended recipients.
For this reason, you should include the last names of John and Jane, and you should omit the word "Cousin" entirely.
I'm not sure I agree with the comments on what the mailman reads. I think that the address needs to conform to standard format, but the final delivery, from mailbox to the hand of the recipient takes place within the home, and so a casual naming seems perfectly reasonable to me.
I'd go with "Cousins John and Jane") though I might include their last names too.
When sending a letter and writing their names on the envelope, which is correct?
Cousin John & Cousin Jane or Cousin John & Jane,
Neither. In the UK, both are wrong.
On the envelope you write "Mr & Mrs J [insert surname]" (The "J" is the husband's initial.)
Nobody is interested in how you are related.
