Rental arbitrage is a real way to run a short-term-rental business without buying a house: you sign a lease with the landlord’s written permission to sublet short-term, furnish the unit, and rent it out night by night for more than your monthly rent. It’s also a real business with real downside — not a way to make passive income with someone else’s property, whatever the “no-money-down Airbnb” videos suggest.
Here’s the gap those videos skip over. Every dollar you make on the spread between rent and nightly rate is a dollar you’re only entitled to keep if the lease actually allows it, the city or council you’re operating in actually permits it, and you’ve budgeted for the months where the calendar doesn’t fill up. Get any one of those three wrong and the arithmetic that looked so clean on a spreadsheet collapses fast — sometimes into an eviction notice, sometimes into a fine, sometimes just into a quiet loss you cover out of savings until you give up.
This guide walks through how the model actually works, the specific things that make it legal or illegal depending on where you are, and what it really costs to get started — using the US, UK, Australia and Switzerland as the four markets, since the rules genuinely differ by country and often by city within the same country.
What is rental arbitrage, and how is it different from owning a rental property?
Rental arbitrage means you’re a tenant, not an owner. You lease a property from a landlord at a fixed monthly rent, furnish and manage it, then re-rent it short-term to guests at a nightly rate that — across enough occupied nights — adds up to more than what you owe in rent. You never hold the deed, never take out a mortgage, and never carry the property’s long-term ownership risk (repairs to the structure, property tax, the landlord’s own loan). What you do carry is the lease obligation: rent is due every month whether or not a single guest checks in.
That trade-off is the whole model. Ownership-based short-term rental means you’re exposed to the property’s value and a mortgage; arbitrage means you’re exposed to occupancy and to a landlord relationship you don’t control. Neither is “safer” — they’re different risk profiles, and arbitrage is the one that lets you start without a down payment, which is exactly why it gets marketed as an easy entry point. It isn’t an easy entry point. It’s a lower-capital entry point into a business that still has real operating risk. (If you’d rather go the ownership route, here’s how the buy-rent-refinance-repeat cycle actually works, and where it breaks.)
Get the landlord’s permission in writing before you do anything else
This is the step that decides whether you have a business or a lease violation, and it has to happen before you sign, not after you’ve already furnished the place.
Most standard residential leases either prohibit subletting entirely or only permit it for long-term subtenants, which is a different thing from nightly short-term guests. Getting your landlord to say “sure, that’s fine” out loud is worth nothing if a dispute ever ends up in front of a judge or your landlord’s own insurer. You need a written addendum, ideally drafted or reviewed by a local attorney, that:
- Explicitly names short-term or “Airbnb-style” subletting, not just subletting in general
- States who is responsible for guest-caused damage and who carries the insurance for it
- Confirms the landlord’s own mortgage lender and insurer don’t prohibit the use (some residential mortgages and landlord policies do)
- Sets out what happens if the local city or council later restricts or bans short-term rentals in that building — because that possibility is real, and covered below
Skip this and you’re not running a business with a legal ceiling on the downside — you’re running one where the ceiling is “whatever the landlord decides today,” which can include termination and eviction proceedings the moment they change their mind or a neighbor complains.
Is short-term-rental arbitrage even legal where you want to do it?
There’s no single answer — short-term-rental law is set at the city, county, borough or cantonal level almost everywhere, and it changes often. What follows is one concrete, currently-in-force example per country, not a full list of every local rule. Before you sign a lease anywhere, check that specific city or council’s own current page — not this article, and not a general summary site — because these thresholds move.
United States: rules set city by city, and some cities effectively ban arbitrage
There is no US federal or state-wide short-term-rental law — it’s set locally, and the difference between neighboring cities can be enormous. New York City is the sharpest example of a city that regulates hard: under Local Law 18, anyone offering a short-term rental (fewer than 30 consecutive days) must register with the Mayor’s Office of Special Enforcement, and — critically for arbitrage — the official registration rules require the host to stay in the same unit as the guests, with no more than two guests at a time. That single requirement rules out the classic “lease a whole apartment, furnish it, rent the whole thing out while you’re not there” arbitrage model in NYC specifically. Booking platforms are also barred from processing payments for unregistered listings, and unregistered operation exposes a host to administrative summonses, potential fines, and loss of registration eligibility, per NYC’s official enforcement page.
That doesn’t mean arbitrage is dead everywhere in the US — plenty of cities register STRs without an owner/host-presence requirement, cap the number of nights or permits instead, or have comparatively light rules. It means you cannot assume your city works like the next one over. Before signing anything, check your specific city’s planning or business-licensing department page directly — search “[your city] short-term rental ordinance” and go to the .gov result, not a property-management company’s blog summarizing it.
United Kingdom: Greater London’s 90-night ceiling, other councils differ
In Greater London, you can let an entire home short-term for up to 90 nights in a calendar year without needing planning permission, under section 44 of the Deregulation Act 2015. Go past 90 nights in the same calendar year and you’re supposed to apply for a change-of-use planning permission — which London boroughs approve rarely, in practice. The counter runs January 1 to December 31, applies to the whole property regardless of which platform booked which night, and boroughs including Westminster and Camden actively monitor listings against it. Miss the limit and ignore a council’s enforcement notice, and you’re looking at planning enforcement action, which is a criminal offence to ignore.
Outside Greater London, the 90-night rule doesn’t apply at all — different councils across the UK set their own licensing and planning approaches, and some have none specific to short lets yet. Whichever UK city you’re arbitraging in, check that council’s own planning or licensing pages, not just the London figure, before you commit to a lease.
Australia: New South Wales caps non-hosted lettings in Greater Sydney at 180 days
New South Wales runs a statewide short-term rental accommodation (STRA) framework. In Greater Sydney specifically, a “non-hosted” STRA — meaning nobody who lives there is present during the stay, which is the arbitrage scenario — is capped at 180 days per year, counted from your registration’s 12-month anniversary rather than the calendar year. You must register the property on the NSW STRA Register first (a $65 initial fee, then $25 a year to renew), and there’s an important carve-out: bookings of 21 or more consecutive nights to the same guest don’t count against the 180-day cap. “Hosted” STRA, where an on-site host is present, isn’t capped at all under this rule — the day limit exists specifically to constrain the arbitrage-style model. Some NSW council areas outside Greater Sydney set their own, sometimes tighter, limits — Byron Shire’s cap is 60 days, well below Sydney’s.
Switzerland: canton-by-canton, and Geneva and Zurich already show how different they can be
Switzerland has no single national short-term-rental law — regulation happens at the cantonal and municipal level, and the two biggest cities already illustrate how differently that can play out. In Geneva, renting out an entire home via a platform like Airbnb is capped at 90 nights a year; go beyond that and the activity is treated as professional, requiring authorization from Geneva’s Police du Commerce, and non-compliance carries administrative or penal sanctions under the canton’s own rules. Guests also owe a nightly tourist tax, which Airbnb has collected and remitted automatically on Geneva bookings since September 2020. Zurich took a different approach: a rule that took effect on September 1, 2026 stops apartments that are regularly rented commercially short-term — Airbnb-style lets and business apartments — from counting toward the city’s mandatory minimum-housing quota, and owners now have to declare that use on any building-permit application, even when no construction is involved. Occasional letting of your own home while you’re away is exempt; running it as a standing commercial operation is what the rule targets.
One more piece of Swiss context worth flagging, since it comes up constantly in “start an Airbnb in Switzerland” content: Lex Koller, the federal law on acquisition of real estate by persons abroad, restricts foreign, non-resident buyers of Swiss property — it’s a purchase restriction, not a rental one. If you’re arbitraging (leasing, not buying), Lex Koller generally isn’t what stands in your way; the cantonal STR rules above are. It matters mainly if the plan was ever to buy the property later — that’s a separate, more restrictive conversation.
What licenses, insurance and taxes does the business actually need?
Beyond the short-term-rental permission itself, arbitrage is still a small business, and it comes with the paperwork a business carries.
Business registration. Depending on where you operate, you may need a local business licence or to register a sole proprietorship or LLC-equivalent entity, separate from the STR registration itself. Check your city or council’s small-business or licensing office — this is usually a different department from the one that handles the short-term-rental permit.
Short-term-rental-specific insurance. This is the one people skip and regret. Ordinary tenant’s or renter’s insurance is written for you living there, not for paying guests cycling through. A standard landlord policy, similarly, generally excludes commercial short-term use. You need a policy sold specifically for STR hosting — sometimes marketed as “host protection” or commercial short-term-rental coverage — that covers guest injury liability, guest-caused property damage, and lost-income business interruption. Get it in writing and confirm the underwriter knows exactly what you’re running before your first booking, not after your first claim gets denied for non-disclosure.
Occupancy and tourist taxes. Most of these markets add a per-night tax on top of the room rate — sometimes collected automatically by the booking platform (Geneva’s tourist tax is one example, remitted by Airbnb directly), sometimes something you have to register for and remit yourself. Confirm which applies in your specific city or canton before you set your nightly price, because it changes your real margin.
How much cash do you need before a single guest checks in?
More than most “start with no money” content suggests. The figures below are a worked, hypothetical example on a modest one-bedroom unit — not a quote from any specific city or property, since rent and furnishing costs vary enormously by market. Use it to see the shape of the cost stack, then build your own numbers from real local rent and furnishing quotes.
Add on top of that: the STR-specific insurance premium, any business licensing or STR registration fee (NSW’s is a modest $65/$25, but check yours), professional photography (guests book off photos), and platform/software costs if you’re using dynamic pricing or channel-management tools. None of it is huge in isolation. Stacked together, before-income startup costs for even one unit can easily add up to five figures once you include the reserve — treat that reserve as non-negotiable, not a nice-to-have. Here’s why.
The model’s biggest weakness: it can end without much warning
This is the part the “passive income” framing leaves out entirely, and it’s the single biggest reason to treat rental arbitrage as a real business rather than a guaranteed spread.
Occupancy isn’t constant. Short-term rentals are seasonal almost everywhere — a beach unit that’s booked solid in July can sit empty in February, and a city apartment near a conference center can swing hard around event calendars. Your rent obligation to the landlord does not move with your bookings; it’s fixed every month regardless of how many nights you filled.
The regulatory ground can shift under you, too, sometimes fast. A council can tighten a night cap, a city can add a registration requirement or a host-presence rule the way New York did, or a canton can introduce a new declaration rule the way Zurich just did in September 2026 — and any of that can turn a working unit into a non-compliant one overnight, with no guarantee your lease terms protect you from the fallout. And the landlord can simply sell the property, decide not to renew your lease, or change their mind about the arrangement — none of which you control, and all of which end the business for that unit immediately, whatever your booking calendar looks like.
None of that means don’t do it. It means underwrite the downside honestly: don’t lease a unit you can’t cover from savings for at least a couple of slow months, don’t assume today’s local rule holds for the life of your lease, and don’t put so much of your personal cash into furnishing and deposits on one unit that losing it would be a financial emergency rather than a setback. If you haven’t built that kind of buffer yet, building an emergency fund before you take on a lease obligation like this is the more boring, more important first step — and the same logic behind not putting all your money into one investment applies here too: don’t let one leased apartment become the only thing standing between you and a bad month.
So is rental arbitrage worth it?
It can be, for people who go in treating it as a small business with real fixed costs, real legal homework, and real seasonal risk — not as a way to get paid for property you don’t own without any of the downside. The margin between rent and nightly rate is genuinely there to capture in a lot of markets. It’s just not free, guaranteed, or immune to a council meeting three towns over deciding to tighten the rules.
Before you sign a lease, run your own numbers on what it actually costs to carry the unit through a bad month — not just a good one. KnowWiser’s budget calculator is a reasonable starting point for working out how much of your own cash you can commit to rent, deposit and furnishing while still keeping the reserve this article keeps coming back to; it wasn’t built specifically for short-term-rental math, but the discipline of separating fixed costs from the buffer you need is exactly the same exercise.
Sources
- NYC Office of Special Enforcement, Registration Rules and Laws and enforcement page (Local Law 18)
- NYC311, Short-Term Rental Registration
- Westminster City Council, short-term lets — the law (Deregulation Act 2015, s.44)
- NSW Government, Short-term rental accommodation — NSW Planning Portal
- État de Genève, Louer mon logement via une plateforme d’hébergement type Airbnb
- Stadt Zürich, Regelung für kurzzeitig vermietete Wohnungen tritt in Kraft (September 2026)
- Federal Office of Justice, Lex Koller / acquisition of real estate by persons abroad
Rules above were checked against these official pages as of September 27, 2026. Short-term-rental law changes often and varies by city, council or canton even within the same country — verify your exact location’s current rule directly with the local authority before signing a lease or listing a property. This article is general information, not legal or financial advice for your specific situation.