There is a U.S. Federal ID Number (EIN) printed on the official donation receipt that the bishop signs and gives to each member. Mine shows: 23-7300405 I don't know whether or not it is the same number for all donors in the U.S.
Interesting. The EIN printed on my year end statement from the ward and also direct from the church from the donations-in-kind folks both match the number rontilby posted above.
So we can better help you, please edit your Profile to include your general location.