The 10-minute monthly close for a rental portfolio

The books on a small rental portfolio don't fall apart in a single dramatic moment. They drift. A repair receipt you meant to log gets buried, a late payment never gets reconciled, an insurance renewal slides by, and three months later you're reconstructing the year from your bank app and your memory — which is exactly the spreadsheet death spiral that made me build this thing.

The fix isn't more software discipline in the abstract. It's a short, identical routine you run on the same day every month, so nothing accumulates. Here's the one I actually run. It takes about ten minutes once the habit is set, and it has four steps. Do it on the same day each month — I do it on the 5th, after the grace period has closed and I can see who genuinely paid late.

Step 1 — reconcile rent received against the rent roll

Start with the question that actually keeps you up at night: did everyone pay? Open the rent roll for the month — the list of every unit, what rent was expected, and what came in — and walk it against your bank deposits. For each unit you're marking one of three things: paid in full, partial, or late with a balance still owed.

The whole point of doing this against a rent roll, rather than just scrolling your bank feed, is that the rent roll knows what was supposed to arrive. A missing payment is an empty row that can't hide. Scrolling deposits only shows you what did come in — you'd never notice the one that didn't. This is the step that catches the late tenant on the 5th instead of the 25th.

If a unit is late, that's also where the late fee gets settled — and if your tooling computes the fee from that lease's grace period, you aren't doing date math by hand or guessing at the amount. You glance, you confirm, you move on.

Step 2 — log the month's expenses

Now the money that went out. Pull up the month's expenses — the plumber, the water bill you cover, the insurance draft, the trip to the hardware store — and enter each one. The discipline that makes this pay off later is sorting every expense into its Schedule E line as you enter it: insurance to insurance, the drain snaking to repairs, water and sewer to utilities.

This is the step that turns tax season from a weekend of archaeology into an export. If each expense is already categorized the month it happens, your Schedule E is essentially writing itself all year. Two things to be careful about while you're here, because they're the costly ones:

• Repairs vs. improvements. A fixed water heater is a repair you deduct now; a whole new HVAC system is a capital improvement you depreciate over years. Tag it right at entry while you remember what the work actually was.
• The mortgage split. Only the interest portion of the payment is a deductible expense. Principal is debt paydown; escrow is money parked for taxes and insurance. If you log the whole payment as one expense, your numbers will be off all year.

Step 3 — check upcoming renewals

With the money in and out handled, look forward. The expenses that hurt a small landlord most aren't the routine ones — they're the ones that lapse in the dark: a landlord insurance policy that quietly renews at a worse rate, a second-half property-tax installment, a city rental license, a lease drifting toward its end with no renewal conversation started.

So scan the next 60 to 90 days. Anything with a date — a policy, a tax installment, a license, a lease end — should be visible here, sorted by how soon it's due, ideally with the document attached so you're not hunting for the policy number when the renewal notice arrives. This is a thirty-second glance, and it's the step that prevents the most expensive surprises.

Step 4 — glance at cash flow

Finally, zoom out. Look at the month's net — rental income minus operating expenses — next to the prior several months. You're not doing analysis; you're looking for a shape that's wrong. A maintenance cost creeping up three months running. A unit that's been quietly underperforming. A month that came in soft. The value of the monthly cadence is that you catch a trend while it's four data points instead of a twelve-month surprise.

That's the whole routine. Reconcile, log, look ahead, glance at the trend. None of these steps is hard; the discipline is doing all four on the same day, every month, so nothing gets a chance to pile up.

Pick a day, and treat it like a bill

The single thing that determines whether this routine survives contact with a busy month is whether it has a fixed day. “I'll get to the books sometime” loses to a W-2 job and a family every time. “The 5th, right after coffee” doesn't, because it competes on the same footing as everything else with a date. I picked the 5th deliberately: most leases land rent on the 1st with a few days of grace, so by the 5th the picture has settled and a tenant who's actually late is actually late, not just slow to hit send.

Pick whatever day fits your leases — the point is that it's thesame day, on a recurring reminder, treated with the same seriousness as a payment you owe. Ten minutes once a month is a rounding error on your time. The version that costs you a weekend is the one where eleven months of un-reconciled rent and un-categorized receipts wait for you in a single April sitting, and half the context is gone.

What to do when a step turns something up

Most months, all four steps are quiet confirmations: everyone paid, the handful of expenses are logged, nothing's due, the trend looks normal. The routine earns its keep on the months when a step doesn't come back clean — and the move there is to turn the finding into a small, concrete next action rather than a vague worry you carry around.

• A late tenant in step 1 becomes a dated note and, if your lease allows, the late fee applied — not a mental reminder to “follow up sometime.”
• A repair in step 2 that might be a capital improvement gets flagged as such at entry, with the invoice attached, so the repairs-vs-improvements call is your CPA's problem in March and not a mystery line.
• A renewal inside 60 days in step 3 gets the actual task started — the insurance quote requested, the lease-renewal conversation opened — because a renewal you merely noticed is the one that still lapses.
• A cash-flow shape that's drifting in step 4 becomes one question to answer next month: is that maintenance creep a one-off, or a building telling you something?

None of these is a heavy lift in the moment. The reason they get skipped in the spreadsheet world is that the finding and the fix live in different places — you spot the late tenant in your bank app, then have to go remember to do something about it later, and later never comes. Catching it and acting on it in the same ten minutes is the whole difference.

Why ten minutes works and an afternoon doesn't

A monthly close stays at ten minutes precisely because it's monthly. One month of rent is nine or ten rows to reconcile, not a hundred. One month of expenses is a handful of receipts you still remember, not a year of mystery charges. The renewals you're scanning haven't changed much since last month. The work is small because it's frequent — that's the entire trick.

The reason resty.ai is built around this routine rather than a once-a-year tax dump is that the once-a-year version is the one that fails. When the rent roll, the categorized expenses, the renewal dates, and the cash-flow view all live in one place, the close is four glances at four screens you already have open. Run it on the 5th, and the rest of the month — and the following March — takes care of itself.