Invitation Replying Etiquette

First, let’s have a look at some suggestions that apply to the entire invitation scene. My mother would rather a rattlesnake bite her than include a reply card in an invitation, but that’s another generation. These days, the RSVP card is a fixture in most social situations. It evolved because so many people stopped replying formally and in writing to invitations without them.
The practical host must decide whether or not to use the reply cards, and either decision is acceptable. However, experience shows that it is far less stressful to use them than to mount a telephone campaign before the event to find out how many people are coming.
Reply cards follow the same style as the invitation and are made of the same stock. If you do not enclose a reply card with your invitation and you need to know who’s coming, be sure to mark the invitation RSVP and provide an address or a telephone number.
When responding to a formal invitation that does not contain a reply card, follow the same general form as the invitation. Write by hand and in the third person. Use conservative stationery or engraved personal stationery. You can use a personal letter sheet, a half sheet, or an informal. Couples responding should use a Mr. and Mrs. informal.