Carl
Level 15

Investors & landlords

Like when we pay for tax software/prepare, computer services, yearly LLC renewal fees with the state, bank fees etc... ?

You allocate those expenses across all of the rentals. If there's note a specific spot in the rental expenses section that covers the expense, then you allocate as a miscellaneous expense across all rentals.

Now we got a business cell phone (and a line) which must be depreciated,

I seriously doubt you paid more than $2,500 for the cell phone. So the purchase price of the cell phone most certainly can be expensed. The monthly charges for the cell phone can also be expensed across all rentals as a utilities expense.

Since rental income appears to be your only source of income, I also question if you are "actively involved" in the rental activity. You may want to confer with a tax professional to see if that income qualifies as non-passive income if it provides more than 50% of your reportable income each year.  If rental income is "truely" you're only income, then you may run into problems on the tax front later down the road when you sell the property. That is, unless you plan to keep the property for the rest of your lives with it being passed on to heirs in your Last Will & Testament. But you should still confer with an estate planning professional.