If cash or a check is received as a gift, do I need to let the person know what I'm going to be using the money for when I write my thank you notes? What should I say?
Dear Simple Q,
Thank you notes for cash (or check) gifts are the same as for any gift. Always let the gift-giver know how much you appreciate their gift. Yes, let the giver know for what purpose you'll be using the money. If you're not sure, then tell them that you're saving up for college, a trip, a new appliance, or other future event or item. It's always nice to end the note by thanking them for their thoughtfulness and generosity, too.
You can mention the amount of the cash gift if you like, and as pointed out by Peggy Post, it lets the "person know the correct amount was received."