The most important thing is tagging every transaction to the correct property. In QuickBooks Online, the best way to do this is with the “class” feature. Create a class for each property (like “123 Main St” or “Unit A - Franklin”) and assign that class to every deposit and every expense. This lets you pull a profit and loss report filtered by property so you can see exactly how each one is performing on its own.

Some investors try to use separate bank accounts for each property. That can work with two or three properties, but it gets unwieldy fast. A better approach is one or two dedicated business accounts with disciplined class tagging on every transaction. The tracking happens in your accounting software, not through your bank account structure.

For each property, you should be tracking rental income, mortgage interest (not principal, which is not an expense), property taxes, insurance, repairs and maintenance, property management fees, HOA dues, utilities you pay, and any travel related to managing the property. Principal payments on your mortgage reduce your loan balance but don’t hit your profit and loss. Getting this wrong inflates your expenses and gives you inaccurate numbers.

Depreciation is another area that needs per-property tracking. Each property has its own cost basis, placed-in-service date, and depreciation schedule. Your accountant needs clean records for each property to calculate this correctly on your small business tax returns. The IRS requires a separate column on Schedule E for each rental property, so if your books aren’t organized by property throughout the year, tax time becomes a painful exercise in sorting through transactions trying to remember which property they belonged to.

Security deposits also trip people up. When a tenant pays a deposit, that’s a liability, not income. It only becomes income if you keep part or all of it for damages. Recording deposits as rental income overstates your revenue and creates tax problems when you return the deposit later.

Set up a consistent process for recording transactions. Whether you do it weekly or your bookkeeper handles it monthly, every rent payment, every repair invoice, and every insurance premium needs to land in the right category and get tagged to the right property. Letting transactions pile up untagged for months means you’ll forget which property that $400 plumbing bill was for.

If you already have properties but your books are a mess, getting caught up is worth the effort. Clean per-property records tell you which properties are actually making money and which ones are dragging down your portfolio. That information drives better decisions about whether to hold, sell, or reinvest.

Real estate investor accounting requires this level of detail from day one. The investors who track properly know their true return on each property. The ones who don’t are guessing, and they’re usually surprised when the real numbers come in.