What should I do if I can’t go?

You can decline an informal invitation by telephone (“I’m sorry, but I have other plans.” “That sounds wonderful, but I’m afraid I can’t make it.”). It is unnecessary to explain in detail why you cannot attend.

If the invitation is formal, and there is no telephone number after the R.S.V.P., then a formal note is appropriate. Written on a neutral–colored card, it might say: