To fill out a wedding response card, an invited guest should complete the card's title line and check the appropriate response to indicate whether or not the guest plans to attend the wedding. The number of guests attending from the household should also be indicated on the line provided if applicable.
Additional notes on a wedding RSVP card are not encouraged on a formal invitation. Informal and humorous wedding invitations sometimes allow room for comments. Guests should feel welcome to write good wishes in the blank space of an informal invitation for the couple to enjoy. Proper etiquette dictates that wedding response cards be promptly returned according to the date requested on the card.
Wedding invitations sent by email, social networks or telephone are automatically considered informal. Responses to these invitations should be informal but also as polite and timely as a formal response. A handwritten response to the host can be sent, but a reply in the same manner of the invitation is acceptable. Even when an invited guest cannot attend, a response should still be sent to notify the host for purposes of a complete headcount. According to Emily Post, once a guest responds with an affirmative answer, only death or illness is considered an acceptable reason to miss the wedding per the rules of etiquette.