Hi @Andy S. 3x monthly rent for income has worked well. 

Quote from @Mordechai Chaimovitz: Can someone please explain to me why people are buying 2 flats that rent comps show $4,600 a month in income for 665k+?

If your firend wants to stay in the place AND has the funds/income to do so, they need to refinance in their name ASAP (as part of the process), not 5 yeas from now, not if they remarry, not 10years from now.   

They're highly popular for turnkey rental properties because qualification is primarily based on the income generated by the property itself rather than the borrower.

At that time, my friend encouraged me to get into real estate with the idea of creating passive income and wealth in future (via appreciation).

Fake income documents are easily purchased online, and inexperienced screeners often miss red flags.

Velocity banking works by taking a huge 'chunk' and putting it down on principal, then paying down the HELOC with every penny of income you get. 

On a commercial asset the value is directly based on the NOI (net operating income).

Use tools like AirDNA or Mashvisor to provide market data on projected rental income and occupancy rates, and make sure your lender works with appraisers familiar with short-term rentals.

The rates are high right now but these loans are limited based on cashflow so you cant take a loan that costs more than you're receiving in rental income.