How do you address wedding invitations with one envelope?

If you are using a single envelope, you need to be clear and formal, because there is no inner envelope to carry extra names. Write the full names and titles of the adult guests on the envelope, for example 'Mr John Smith and Ms Jane Brown'. If children are invited, add their names on the next line, such as 'and Emily and Oliver Smith'. This avoids any guesswork and makes sure everyone knows who is included. For a married couple with the same surname, 'Mr and Mrs John Smith' works, but you can also write both first names if you prefer a modern feel. For a family, write the parents' names first, then the children's names below. If you are inviting a guest with a partner whose name you do not know, address it to the guest and 'and guest' on the second line. The outer envelope is sealed, so make sure the address is complete and correct. You can still add a handwritten note inside if you want to be more personal. The main rule is clarity: the envelope should tell guests exactly who is invited, so no one feels left out or unsure.