There are differing opinions on the etiquette of thank-younotes when it comes to time frames, but in general, couples should send all thank-younotes within 90 days of receiving the gifts. This is a large undertaking, and the more organized a bride and groom arewhen sending out invitations, the easier thank-younotes will be.
According to Cindy Hobson, wedding etiquette expert for The Knot, the rule depends on when the couple receives the gift. If they receive the gift before the wedding, then they have 2 weeks from the gifts delivery to get the note out. If they receive the gift during or after the wedding, then they have 1 month from the time they return from their honeymoon. However, it has become generally accepted that newly weds have a 3-month grace period to send out their thank-younotes.