This article is from the Paper Money Collecting FAQ, by Bruce Giese firstname.lastname@example.org with numerous contributions by others.
Society of Paper Money Collectors (SPMC)
Bob Cochran, Secretary
P.O. Box 1085,
Florissant, MO 63031 USA
The SPMC is mostly for US paper money collecting. I
believe they've been around since 1963.
Professional Currency Dealers Association (PCDA)
P.O. Box 573
Milwaukee, Wisconsin 53201 USA
You can't join this group as it's just for dealers.
Send SASE for free list of members (i.e. respectable dealers).
Also, send 59 cents for the booklet "How to Collect Paper Money"
International Bank Note Society (IBNS)
A good organization for learning about paper money. They also
have frequent large mail-in auctions and an enormous library
accessable by mail. The IBNS Journal is a fairly scholarly
source of info and free ads for non-dealers. They have a few
P.O. Box 1642
Racine, WI 53401
Assist. General Secretary
36B Dartmouth Park Hill
071 281 0839
Latin American Paper Money Society
Arthur C. Matz, president
3304 Milford Mill Rd.
Baltimore MD 21244
Publication: "Lansa" three times a year.
Canadian Paper Money Society (CPMS)
P.O. Box 562
Hell Bank Note Collector's Club
Mr. William Etgen, Secretary
3600 Whitney Avenue
Sacramento, CA 95821-3128
Collecting Hell notes from around the World.