Hi Carlo,
I have been originating private money and commercial notes for close to 10 years.
My understanding is that you don't need a license to buy any paper (notes).
You only need a license to originate paper if the loan falls under the TILA RESPA guidelines. Basically, if you are lending on someone primary residence is when things get sticky with disclosure laws, timelines, terms, etc.
The easiest way to avoid the licensing issues is to simply lend money, or buy paper on investment properties. 90% of the states do not require a license to originate, lend, or buy and sell paper if the subject property is Non Owner Occupied, ie: Business Purpose Real Estate, ie Investment Property.
That is what all the hard money lenders do, and it allows them to lend nationwide without getting tagged for licensing issues.
States that do require a license to lend/broker on 1-4 Resi Investment Properties:
CA, ID, OR, NV, AZ, UT
States that do require a license to lend/broker on 5+ Multi/Mixed Use or Commercial properties:
CA, ID, OR, NV, AZ
**not legal advice - do your own research.