Typically, thank you cards are ordered at the same time as the invitations and other major elements of the wedding stationery package. You could wait, but there's really no reason to unless you have budget constraints. The thank you cards should be similar in design and tone to your invitations. Remember you want a consistent style for all of your stationery.
Additionally, you should order one thank you card for every invitation you plan to send out and for about 25% of the announcements you send. You should also order a thank you card for every member of your wedding party, for all of your wedding vendors, and for everyone who takes part in the ceremony, such as performers and your clergy. As always, you should order between 10 to 25 extra thank you cards in case you make mistakes or you get more gifts than you anticipated.
Thank you cards are a must for every bride-to-be. While you're planning your wedding and well after bridal shower and your wedding day, you will have many occasions and uses to send a thank you note. Make sure you have a stash of notes on hand so you can always promptly send a quick thank-you. We have a wide variety of charming and unique notes to add panache to your wedding stationery.