I've never looked at title reports, but it's fairly common for people to buy a unit, live in it for X years, move out, buy another place and then rent out their

I've never looked at title reports, but it's fairly common for people to buy a unit, live in it for X years, move out, buy another place and then rent out their old place. I also don't remember about making specific declarations that certain units are my 'primary residence for the year' on my tax return ever. Did the title report say he bought it as a primary residence? Did their original mortgage continue as a 'primary residence mortgage' on the unit. That would make sense then and he wouldn't be doing anything bad AFAIK. Also as a landlord you don't need a rental unit to be a primary residence anyway, because you can actually deduct way more than just your mortgage interest, and the property taxes I think are deductible as a biz expense that is independent of the $10k personal SALT limit too, so there is no incentive to do stuff like that unless the income was unreported also.