In order to plan successfully, start with the time an invitation should arrive. Important conferences or seminars, especially those lasting several days, requiring travel should be made six to eight months in advance. For an important dinner that requires out of town travel, allow four to six months. Luncheons require three to five weeks notice. Evening receptions in conjunction with another event require four weeks notice.
Cocktails require two to four weeks notice, as do large breakfasts.
Teas require two to three week. Work in reverse from the date the invitation should arrive. Formal invitations must be addressed by hand in black ink. Informal invitations are more effective when addressed by hand, although individually typed envelopes are acceptable. Always use stamps rather than a postage meter.