I keep photos and/or invoices as needed as well.

In the case where I had one tenant's parents pay ahead and the other paying monthly, I still send them a monthly invoice indicating the balance left on the account. 

I struggled through and got my QB set up before finding Bigger Pockets, but if I had to do it again, I would use Nancy's book.With QB, you can email monthly invoices to your tenants. 

However, any request outside of the scope will receive an invoice the following week.

@Phil Weinstein A paid invoice and a waiver of lien is typically what you will receive.

If you use QuickBooks, you can invoice tenants for rent and also send a separate invoice for the additional billing of sewer bill.  

If that isn't a possibility, include in lease that tenant agrees to pay 50% of total bill then send them an invoice.

OR the income collected for Feb. rent invoices no matter when they were paid i.e.

Rent becomes income when received - - it's that easy.The fun comes in when we consider IRS+State taxation vs how a Bank may see it.Follow this:1) each month you issued invoices and receive payments2) you also record Billings and Payment.Now run the Pnl To Date or PnL This Month and you will see:Gross incomeTotal ExpensesNet ProfitsThe rents collected are in your Gross, the expenses all show up on the Sch EThe PnL shows NOTHING for Reserves/CapExp nor Vacancies because they are neither Income Nor Expenses and thus none show up on the Sch E.The items: Reserves, CapExp, Vacancies are used ONLY for prudent cost accounting and management to 'help' you manage a self-sustaining property.

Is doing the financials generating detailed reports and a bunch of calculations or is it paying invoices for lawncare and the water bill?