Why not stop selling on that account and open a few more and then you won't have to worry?
Agreed, run multiple accounts. I am surprised your account hasn't been locked from receiving funds and closing the account if you are that close to the mark this early in the year.
Hitting almost $20,000 without being asked for a SSN is impressive. Have you never withdrawn money before?
That is a good probe question - OP is operating well but the use of multiple accounts as suggested by other thread contibutors is a VERY wise move for future business.
You should be find giving them EIN. They dont match the name with ein number as it is for business and owner could be anyone. Or open a new paypal account and use that ein numbwer!