Hello BP, I am looking into purchasing my first duplex, which I will be owner occupying. I have a question about how to manage my banks accounts. I want to keep my personal income/expenses separate from my business income/expenses, however this will be tricky because the rent will not fully cover the business expenses. This means that my business checking account will go negative and be closed unless I pump personal money into it. My tentative plan is to do the following: Person Checking Account: +Salary (from W-2 job) -1/2 PITI -personal groceries, gas, spending, etc. Business Checking Account: +Rent -1/2 PITI -Business Expenses My rationale is that only half of the PITI is used for business and the other half is a living expense for me. Let me know if anything is unclear or if you have suggestions on how to handle the two checking accounts. Thank you!

For house hacking, I don't think it's necessary to separate everything. More trouble than it's worth. 

At tax time, just allocate your expenses between person and the rental. 

everything will wash in taxes anyway, not that important to separate. Essentially, you're having a tough time because they aren't really that separate. The business doesn't stand on it's own it's being subsidized, which is perfectly fine.

If you insist on keeping them separate, than I say pick whatever is easiest. There is no accounting difference.

Thank you for the quick responses! That makes a lot of sense.

@Alex Hogenson

If you own the property outside of an entity - There is no need to keep a separate record for personal and business expenses. However, it can be useful for record keeping purposes.
Just remember to keep track of your expenses so its easy to provide your accountant and in the case that you get audited.

If you acquire the property within an LLC - you need to keep personal and business items separate(no commingling) or you may potentially risk losing the liability protection afforded by the entity.