Most landlords lose money at tax time not by paying too much tax but by failing to claim what they already spent. The fix is boring and it works: one account, one category list, and a habit that takes two minutes a week.
Open a separate account. This is the whole trick.
One checking account and one card, used only for the rental. Nothing personal on them, ever. That single decision does more for your bookkeeping than any software, because it turns categorising a year of transactions from an act of memory into an act of reading.
If you own through an LLC it is not optional. Mixing personal and business funds is the classic argument for piercing the corporate veil, which removes the liability protection the LLC existed to provide. Multiple properties are usually fine in one account as long as you tag each transaction to a property, though a separate account per property makes per-property reporting effortless.
Use the categories the tax form already uses
Do not invent a chart of accounts. Schedule E has the categories, so track to them from day one and the return fills itself in: 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.
The commonly missed ones are worth naming. Mileage driven for the rental is deductible at the standard rate, and it adds up faster than people expect. So do bank and payment processing fees, software subscriptions used to run the property, home office space if you qualify, professional education, and the portion of your phone bill used for the rental.
Repair or improvement, and why it matters
This is the distinction that changes your tax bill most. A repair keeps the property in working order and is deducted in full this year. An improvement betters the property, restores it, or adapts it to a new use, and must be depreciated over years, typically 27.5 for residential rental property.
Fixing a leaking pipe is a repair. Repiping the building is an improvement. Replacing a broken window pane is a repair. Replacing every window is an improvement. Patching a roof is a repair, and a new roof is not.
Two safe harbours help small landlords considerably. The de minimis safe harbour lets you expense items under a per-item threshold, currently $2,500 for taxpayers without an applicable financial statement, if you elect it. There is also a safe harbour for small taxpayers covering modest annual amounts spent on a low-value building. Both require an election on the return, so tell whoever prepares it.
Receipts, and the two-minute habit
The rule of thumb is a receipt for anything over $75, and honestly, keep them all. Photograph the receipt when you get it and attach it to the transaction rather than filing paper in a shoebox. Digital copies are acceptable to the IRS. Keep records at least three years from filing, seven if you want to be comfortable, and keep anything touching a property's cost basis for as long as you own it plus three years, because you will need it when you sell.
Then make it weekly. Fifteen minutes each week categorising the transactions that came in beats a lost weekend in April every single time, and the categories are still fresh enough that you remember what they were. If you would rather have the transactions pulled in and pre-categorised for you, that is what expense tracking and the bank feed do. The feed is read only: it drafts the entries and you approve them, and it never posts anything on its own.
