Miss, Ms., or Mrs.? Guest or guest? Who's name do I put first? Is it different how do I address an envelope to a married couple versus unmarried couple? Addressing wedding invitation envelopes with proper etiquette is confusing, so many rules and you don't want to offend anyone. No worries! Get my guide below to help you out. And to the last question, yes it is different. If I am designing your wedding invitations and you are still confused, I will take care of the etiquette for you!