How do I enter interest received on a personal loan?

Interest received on a personal loan is taxable and reportable on your tax return.

 

You enter this interest as if you have received a form 1099-INT.

 

In TurboTax, you can enter interest received by following these steps:

 

1. In TurboTax, open your tax return
2. Click on Federal in the left-hand column, then on Wages & Income 
3. Locate the section Interest and Dividends and click on the arrow on the right
4. Click Start next to Interest on 1099-INT.

Would it be the same for interest received on a private/personal loan backed by property in another state?  It's technically interest on a promissory note, not a mortgage.  I will be adding the interest as income to my Federal and home state returns, but would I have to also file a return in the other state as well?

No, you do not need to file a return to report the interest income to the other state.