Can interest the interest on a personal loan against a home (instead of a mortgage from a bank) be deducted?

[Bsch4477]

No deduction unless the loan is secured by a lien on your home and that is clearly documented. 

[Opus 17]

To be counted as a deductible mortgage, the loan does not have to be made by a bank, but the loan must be secured by the home.  The generally means that you signed a promissory note allowing the lender to take your home if you fail to make payments, and (depending on state law) the note must be "perfected" by being filed as a lien against the property at the county clerk's office where deeds and titles are recorded.