I got my Series 7 without any sponsorship.
I applied to become a US broker-dealer in 1998 and become a member of the NASD.
I live in Canada... and had ZERO US securities credentials.
The application process can take about 6 months...
So during this period the applicant who will be the General Securities Principal...
I had to do 3 exams in a certain order...
Series 7, Series 24, and Series 28.
Also had to do Series 55 a few years later.
The only one that was hard... is the Financial Principal Series 28.
The world is full of exemptions and loopholes... ya gotta be creative.