You sign a two-year lease on a two-bedroom apartment, put $8,000 into furniture and photos, list it on Airbnb, and within three months you're running what looks and feels like a rental property business — except you don't own a single brick of it. This is rental arbitrage: lease long-term, sublet short-term, pocket the spread. It's one of the few ways to get into short-term rental income without a down payment, and in the right market it can throw off a 20–30% net margin on a $3,000–$15,000 startup cost.
It's also a business model that quietly breaks half the assumptions baked into normal rental-property bookkeeping. If you set up your books the way a QuickBooks template or a landlord friend tells you to, you'll misclassify your biggest monthly expense, try to depreciate an asset you're not allowed to depreciate, and have no real idea which of your units is actually making money until the lease is already up for renewal.
Here's how to build books that match what rental arbitrage actually is — a lease-based operating business, not a real estate investment.
Rental Arbitrage Isn't Real Estate Investing — Your Books Shouldn't Pretend It Is
The single biggest bookkeeping mistake in rental arbitrage is importing the chart of accounts from a landlord's playbook. A landlord who owns a rental property has a mortgage, builds equity, and depreciates the building over 27.5 years. An arbitrage operator has none of that. You have:
- A lease payment, not a mortgage payment. It's a pure operating expense with no principal/interest split and no equity building underneath it.
- No building to depreciate. You don't own the structure, so Section 168 depreciation on the property itself is off the table entirely — that's the single clearest structural difference from owning a short-term rental.
- A short lease term, not a 30-year hold. Most arbitrage leases run 1–3 years, which means your economics live and die by month-to-month cash flow, not long-term appreciation.
What is depreciable is anything you personally bought and could carry out the door if the lease ended tomorrow: furniture, mattresses, smart locks, kitchenware, decor. A furniture package for a two-bedroom unit typically runs $5,000–$15,000, and the standard practice is to amortize it over 3–5 years — call it $150–$250 a month in furnishing cost per unit. That number belongs in your monthly unit economics right next to the lease payment; leaving it out is how operators convince themselves a break-even unit is actually profitable.
Set Up One Rent Expense Account — Not One Per Unit
The instinct when you're running multiple units is to build a mirror chart of accounts for each one: "Rent – Unit A," "Rent – Unit B," "Utilities – Unit A," and so on. Don't. That approach turns your chart of accounts into an unmanageable mess the moment you add a fourth or fifth property, and it makes cross-property reporting (which units are actually worth renewing?) needlessly hard.
Instead:
- Create one "Rent Expense" account at the top level of your chart of accounts for every master-lease payment you make to a landlord.
- Tag or class every transaction by property, not by account. Most accounting tools (and property-specific platforms built for this, like REI Hub) support a property/class dimension that sits alongside your normal accounts — use it for every line item: rent, utilities, cleaning fees, platform payouts, supplies.
- Never book a lease payment as a loan or mortgage. It's rent, full stop — a straightforward, tax-deductible business operating expense, not a liability paydown.
This gives you two views of the same data: a normal P&L for the whole business, and a per-unit report that answers the only question that actually matters — is this specific lease still worth renewing?
Track Every Unit's Margin Separately, Every Month
Because you're paying a fixed lease regardless of occupancy, rental arbitrage margin is a lot less forgiving than owned short-term rental margin. A slow month on an owned property still builds equity in the background. A slow month on a leased unit is just a loss — the landlord gets paid whether or not you had guests.
Build a simple monthly per-unit P&L with:
- Revenue: gross booking payouts from Airbnb/Vrbo, net of platform fees
- Rent expense: the master-lease payment
- Furnishing amortization: the $150–$250/month figure from setup costs
- Utilities, cleaning, supplies, guest fees
- Insurance (see below — this is a real, non-optional line item)
- Net margin, both in dollars and as a percentage of revenue
Run this by unit, every month, without exception. The operators who get burned in arbitrage are almost never the ones with a genuinely bad market — they're the ones who didn't notice one specific unit had been quietly losing money for four months because everything was blended into one company-wide P&L.
The Lease Itself Is a Compliance Document, Not Just an Expense Source
Before any of the bookkeeping above matters, the lease has to actually allow what you're doing. Most standard residential leases prohibit subletting outright, and a landlord's verbal "sure, go ahead" protects you against exactly nothing — if the building sells, the landlord changes their mind, or a new property manager takes over, an unwritten agreement collapses and you can be evicted with no recourse. You need one of two things in writing before you spend a dollar on furniture: an explicit subletting/STR clause in the lease itself, or a signed addendum from the landlord.
Legality in most markets sits on three layers, and you need clearance on all three, not just one:
- The lease — written landlord permission to sublet short-term
- City/county regulation — a short-term rental permit or registration where required
- The platform's own terms — Airbnb/Vrbo policies on the listing
Skipping the city layer isn't a paperwork risk you can shrug off — some cities fine unregistered STR operators $500 to $10,000+ per violation, on top of forced delisting. Keep your lease addendum, business license, and any STR permit numbers in the same records folder as your books; if a city or platform ever asks for proof, "I have a folder for that" is the difference between a five-minute response and a shut-down listing.
Insurance Is a Recurring Expense, Not a One-Time Purchase
A standard renter's insurance policy explicitly excludes commercial activity in most states, and a normal landlord policy won't cover a subletting business operator at all. Rental arbitrage realistically needs three stacked layers of coverage:
- Renter's/contents insurance for the furniture and equipment you own
- Commercial general liability — increasingly required at a $1 million-per-occurrence minimum by cities issuing STR permits, and the layer that actually protects you if a guest is injured (a single slip-and-fall claim can run well past $50,000)
- Platform host protection (e.g., Airbnb's AirCover) — which only covers bookings made through the platform, not direct bookings
Book all of it as a recurring monthly operating expense per unit, the same way you'd book rent. Treating insurance as a rare, forgettable annual purchase instead of a standing line item is how operators end up under-insured — or worse, uninsured — precisely when a claim shows up.
Schedule C, Not Schedule E: Know Which Tax Bucket You're In
Because you're providing a service-heavy, short-stay product rather than passively renting real estate, the IRS generally treats rental arbitrage as a trade or business, not passive rental activity. The rule of thumb: if the average guest stay is seven days or less, or it's under 30 days and you provide substantial services (housekeeping during the stay, linens, concierge-type touches), that income lands on Schedule C, not Schedule E — which means it's subject to self-employment tax on top of income tax.
That's a materially different tax picture than a landlord filing Schedule E, and it changes what "keeping clean books" needs to support: you'll want expense categories that map cleanly to Schedule C deductions (rent, supplies, insurance, furnishing depreciation, platform fees, utilities) and a bookkeeping cadence that supports quarterly estimated tax payments, since self-employment income doesn't have anyone withholding for you.
Security Deposits: Don't Book Them as Expenses
The upfront cash for a new unit is heavier than most first-time arbitrage operators expect — first month's rent, plus a security deposit that typically runs one to two months' rent, occasionally with last month's rent held in escrow too. On an $1,800/month unit, that's $3,600–$7,200 in cash tied up before a single guest checks in.
A security deposit isn't rent and isn't an expense when you pay it — it's a receivable, an asset on your books representing cash you expect back (assuming no damage) when the lease ends. Booking it straight to "Rent Expense" overstates your costs in the month you paid it and understates them later if the deposit doesn't come back in full. Keep it in a dedicated asset account and only move it to an expense line if and when the landlord actually withholds part of it.
A Simple Monthly Bookkeeping Checklist
For each unit, every month:
- Book the master-lease payment to Rent Expense, tagged to the property
- Record furnishing amortization ($150–$250/mo per unit as a rule of thumb)
- Reconcile platform payouts (Airbnb/Vrbo) against actual bookings
- Book insurance, utilities, cleaning, and supply costs to the property
- Pull a per-unit P&L and check net margin against your target (aim for that 20–30% range)
- Confirm STR permit/registration status is current for every jurisdiction you operate in
Keep Your Finances Organized from Day One
Rental arbitrage is unforgiving of messy books in a way that owning property isn't — there's no equity cushion quietly building in the background while you sort out your chart of accounts later. Every unit needs its own clean, current picture of rent, furnishing costs, insurance, and margin from the day you sign the lease. Beancount.io provides plain-text accounting that gives you complete transparency and control over your financial data — no black boxes, no vendor lock-in, and books simple enough to tag by property without drowning in duplicate accounts. Get started for free and see why developers and finance-minded operators are switching to plain-text accounting.