Is there a tax on stamps?

Question

I was just wondering if there is a tax on stamps or not or is a book of them exactly $8.40 out the door?

Answer 1

it is exactly 8.40 no tax what so ever

Answer 2

To purchase a book of 20 US 42c stamps you would pay exactly $8.40.

This is not necessarily the case if you buy a book of stamps in another country!  Some countries do apply a sales tax to stamps at the time of purchase.

Just a little note for readers not in the US, especially as the question does not specify the country where the purchase would be made!