Passport allows you to be in the country for 6 months.

This requires an unexpired passport and bank statements showing down payments and closing costs which would need to be translated and in U.S.

He is US based with US assets, but he does have a foreign passport.

Hey Daniel,I have dealt with this at previous companies I have been at.We did require a passport of some sort.I will say, we never had any issues with any of the tenants that rented with no SSN.

The smallest upfront fee was $1200 and the largest $10,000. 58 of the lenders required copies of our passport.14 lenders were in the criminal data base of Interpol; 28 were in the in the financial crimes data base of Nigeria and 4 were listed in the Interpol data base connecting them to Russian mobs!

Hello:Could someone please recommend rental management portals that you have used or use to securely store your tenants sensitive documents like passport?

You can verify their identity and their authority to work by reviewing their passport, Form I-9, etc. 

Passport 3.

Also, do I need a passport?

It should have been Puerto Rico since it's part of the US and Americans don't need a passport to get there.