Landlord Bookkeeping Basics and What to Hand Your Accountant

By the Prizm P.M. team at STS Automatic LLC · Last reviewed September 18, 2026 · 8 min read

Rental bookkeeping is not accounting for its own sake. It decides how much tax you pay, whether a lender will touch your next purchase, and whether you can answer the only question that matters: is this property actually making money?

Separate the money first

Open a dedicated checking account for rental income and expenses, and route everything through it. Mixing personal and rental money makes your books unreliable, complicates your Schedule E, and — if you hold property in an LLC — weakens the liability protection you formed the LLC to get.

If you hold security deposits, keep those in a third account. They are not your income.

Cash basis, and why it is enough

Nearly all individual landlords report on the cash basis: income counts when you receive it, expenses count when you pay them. Rent received in December for January is December income. That simplicity is a feature — you do not need accrual accounting to run a handful of units well.

The categories to track

Match your categories to Schedule E so the year-end return is a transcription job rather than a reconstruction: advertising, auto and travel, cleaning and maintenance, commissions, insurance, legal and professional fees, management fees, mortgage interest, other interest, repairs, supplies, taxes, utilities, and depreciation.

Track everything per property — and per unit in a multi-unit building. Portfolio-level totals hide the one property that is quietly losing money.

Repairs versus improvements

A repair keeps the property in working condition and is deductible in the year you pay it. An improvement adds value, restores the property, or adapts it to a new use, and is capitalized and depreciated over years. Patching a roof is a repair; replacing it is an improvement. Fixing a broken window is a repair; replacing every window with double-glazing is an improvement.

Two safe harbors help small landlords: the de minimis election (generally items up to $2,500 per invoice line expensed immediately) and the small-taxpayer safe harbor for buildings. Both require an election on the return — worth raising with your tax preparer.

Do not forget depreciation

Residential rental buildings depreciate over 27.5 years on the building value only — land is never depreciated. Depreciation is a real deduction that costs you no cash, and it is not optional in effect: when you sell, the IRS recaptures depreciation you were allowed to take, whether or not you took it. Skipping it does not save you anything.

Documents to keep, and for how long

• Leases and amendments — through the tenancy plus the statute of limitations in your state.
• Rent records and payment receipts — at least three years, seven is safer.
• Invoices and receipts for every expense — three years minimum.
• Purchase documents, closing statements and capital improvement records — for as long as you own the property, plus three years after you sell. These set your basis at sale.

Digital copies are acceptable to the IRS. A photo of the receipt attached to the expense record beats a shoebox every time.

Numbers to watch monthly

• Collected versus billed. If it is not 100%, you have a collections problem to name early.
• Net operating income — income minus operating expenses, before debt service.
• Cash flow — what actually lands after the mortgage.
• Maintenance per unit — a unit consistently above the others is telling you something.
• Vacancy days — the most expensive line item nobody records.

Where Prizm P.M. fits

Prizm records each rent charge, each payment and each maintenance expense against a specific property and unit, so the monthly and annual reports come out of the same data you already entered to collect rent. You can export any date range to CSV or PDF and hand it to your accountant in January instead of rebuilding the year from bank statements.

General information, not tax advice. Elections, safe harbors and depreciation treatment depend on your situation — confirm them with a CPA who works with rental property.