What rarely-considered expenses do I need to budget for?

[Brianne H.]

Hello, I am interested in purchasing buy and hold out of state 2-4 unit properties in the next year. I understand when doing the math to calculate cash flow, after PITI, you still need to factor in property management, vacancy, and cap ex. However I'm wondering what other expenses have come up, perhaps on a yearly basis (or even less frequently) that I should be considering in my calculations? So far I'm thinking:

- Accounting/doing taxes (how much does this run you per year?)

- Travel expenses checking in on the properties every so often

- Software (Do you use it, or is that more for the PM? How much does it run you?) 

- ?? 

On a similar note, what amount do you keep in reserves per unit? (I'm assuming that's considering for vacancy, % of insurance deductible for the property, cap ex/planned upgrades, and emergency repairs - how much?) 

What else am I missing?