here's what the IRS says
Domestic Partnerships
Except as provided below, every domestic
partnership must file Form 1065, unless it
neither receives income nor incurs any
expenditures treated as deductions or
credits for federal income tax purpose
however, there is the possibility that sooner or later the IRS will send you a notice asking why you haven't filed. you then can write back there was no partnership. to stop this from happening downloading a 1065 form from the IRS website only fill out name and address and mark initial and final. Thus the IRS will know that it should not be looking for a return in the future.
now the bad news that SSN has been assigned to a entity the the IRS believes is a partnership so you can not use it in your sole proprietorship. you must apply for a new one. using the old number may put the IRS on notice to look for a 1065 and you will have issues if you use it on your 1040
