Some musicians I know have MBAs and what-not, but most of us are pretty hopeless at finances, and that would include making a living. For years this band has gone through (legal) hoops to avoid having any one member of the band pay any other more than $600, to try to avoid having to deal with the dread W-9 employee tax forms; but from 2011 on, you play a lot of gigs wid me and the Buskers, you gonna have to cough up your social security number. I now have an EIN, baby--(that's an Employer Identification Number to you).
My hand was forced on this because I just sold a couple of instruments overseas. If the value is over a certain amount, I learned (eventually) that the U.S. government requires you to have an EIN number, as well as the mysterious ITN and a few other pain in the ass forms. I won't bore you with all of it, but I should warn you that though the people at my local Fedex office (in Concord, NH) are very nice, they haven't been taught squat about international shipping or what paperwork you need, which held the shipment up for many days while I scrambled and my buyer worried.
I didn't know this at first. They took my $758 and the two packages, wrapped them in FRAGILE! tape and... bon voyage. I went away on holiday and when I checked my email I found out the packages never left New Hampshire. So I drove home and stopped by Fedex again -- a Friday in August and the aircon in the office had died hours before (of course). It was at least 85 degrees in there and no one could help me. Finally they handed me a phone to talk to an actual international shipping Fedex person who saw me through all the mystifying jargon and forms, got me in touch with customs and the IRS, and basically held my hand until those packages were on their way to Europe, for which I'm very grateful.
A few days later I got my EIN number in the mail. Oh, I'm a big shot now.