Formality has changed a lot over the years, especially as email and texts have taken over for written correspondence. Your wedding is one of the few times in your life when you're going to be really focused on how you communicate in a written manner, especially when it comes to the etiquette of addressing wedding invitations. Nowadays, a woman might be the person in a relationship with the more advanced title, and couples are living together long before they're engaged or married. So can you tailor how you address an invitation to each couple on your guest list? Here's what our experts think.
The great thing about wedding invitations is that, while your friends will be so excited to see your invite hanging on one another's refrigerators, people don't usually save the envelope along with it. So if you decide to use different language to address one couple vs. another, the only people who will know are you, your fiancé, and the guests in question. So while it might require a little more organization on your part, you can definitely choose how to address invitations based on the people they're being sent to.
If you're sending an invitation to an older couple, err on the side of formality. You would address the envelope to "Mr. and Mrs. Michael Brown," "Dr. Susan and Mr. Michael Brown," or "Dr. and Mrs. Michael Brown." If you're inviting a widow, ask a family member who is closest to her whether she would prefer to be addressed by her married name (Mrs. Susan Brown) or by her husband's name (Mrs. Michael Brown). And remember that whichever half of the couple "outranks" the other (say, a doctor, member of the military, or some other profession that includes a title) goes first, regardless of gender.
For a younger couple that isn't married, put the person you know best first, using the appropriate titles — "Ms. Susan Andrews and Mr. Michael Brown" or "Ms Susan Andrews and Ms. Jacqueline Brown."
If you're hosting a more casual event, you might be tempted to just use first names. While this isn't traditional, if the vibe is really backyard barbecue or a picnic in the park, you may be able to get away with it. But this is definitely the right time to use more formal wording for older or more conservative guests — they may not notice that you were being particularly respectful, but they definitely will if they feel that you were too informal!