Mercer County, New Jersey Short-Term Rental Regulations: A 2026 Guide For Airbnb Hosts

Do you own a place in Mercer County, New Jersey and you're weighing whether to put it on Airbnb or Vrbo? Well, the good news is that New Jersey leaves that call almost entirely to your own town, and several of Mercer County's municipalities still let a legitimate short-term rental operate. The catch, and you should hear it before you spend a dollar on furniture, is that the county's answer isn't one answer. Robbinsville Township banned short-term rentals outright back in 2019, Trenton runs a registration program that welcomes them, and Princeton rewrote its rules from scratch in December 2025. Where you land depends entirely on the municipal line your address sits inside.

That split runs the length of the county, and it's worth seeing the shape of it up front. Trenton, the state capital and county seat, takes the lightest touch: register with the city, pay $300, and a short-term rental is legal there as long as it clears a housing inspection every five years. Princeton went the opposite direction from a blank page, since its council adopted a brand-new ordinance that limits hosting to owner-occupants, charges a $200 permit, and phases out every non-owner Airbnb over three years. Mercer County government itself stays out of the whole question. Its Planning Department reviews subdivisions and site plans, not who's renting a spare room on Airbnb, so there's no county permit, no county registry, and no county occupancy tax stacked on top of whatever your municipality decides.

So let's walk through what it takes to do this properly in 2026: which towns still allow a short-term stay, what registration or a permit looks like where one exists, the tax layers that stack on top, how seriously any of it gets enforced, and who to call once you know which office owns your question. Everything below comes from each town's own ordinance and New Jersey's own tax bulletins, checked in July 2026, and where something is still moving I've said so plainly. If you're weighing a Mercer County property against a market where the whole unit can legally go on Airbnb without any of this friction, run both through BNBCalc first.

What are Short-Term Rental (Airbnb, VRBO) Regulations in Mercer County, New Jersey?

Before you run those numbers, it helps to see where Mercer County's rules come from, because almost none of them come from the county. New Jersey's Division of Local Government Services tells municipalities plainly that "rental of short-term transient accommodations is largely subject to municipal ordinance" (Local Finance Notice 2026-09), and the one enabling statute, N.J.S.A. 40:52-1(n), lets a town license short-term rentals but never forces it to. So the state handed the pen to Princeton, Trenton, Robbinsville and the county's other municipalities, and each one wrote its own answer, or in a few cases wrote nothing at all.

Four towns give you almost the whole picture. Princeton's short-term rental ordinance is the newest and strictest: only an owner-occupant can run one, under a permit that took online applications starting January 5, 2026. Trenton runs the opposite model, since its Chapter 228, adopted in December 2019, treats a short-term rental as a normal thing to register for rather than something to restrict, provided the unit isn't rent-restricted, isn't the subject of open code violations, and hasn't racked up repeat complaints. Robbinsville Township took the hardest line of the four, since a 2019 ordinance bans "transient accommodations" completely. No carve-out, no grandfather clause.

Hamilton Township is the fourth, and it's the one that trips people up. It's the county's most populous municipality by a wide margin, so you'd expect a clear rule either way. It doesn't have one. A careful search of its actual code turns up no chapter dedicated to short-term rentals at all as of this pass, and that's not the same as permission, since general zoning and the township's ordinary rental change-of-occupancy process still apply. A Hamilton Township host is working from the general Land Use ordinance, not anything Airbnb-specific. The same is true across most of the rest of the county: West Windsor, Lawrence Township, Ewing, Hopewell Township. No dedicated short-term rental ordinance turned up for any of them in this research pass, so whatever rule exists is buried in ordinary zoning and rental-registration language rather than spelled out anywhere convenient. Do check directly with your own municipal zoning office before you list anything, because "no dedicated ordinance" is a research finding, not a green light.

Starting a Short-Term Rental Business in Mercer County

Since the rulebook changes at every municipal line, starting a business here means auditing your own town before you spend anything on furniture or photography. Here's roughly where Mercer County's municipalities stood as of July 2026:

Municipality	Short-term rental stance
Princeton	Allowed for owner-occupants only, under a permit; non-owner units phasing out through 2029
Trenton	Allowed with annual registration and a housing inspection every five years
Robbinsville Township	Prohibited outright (Ordinance 2019-48)
Hamilton Township	No dedicated ordinance found; general zoning and rental rules apply
West Windsor, Lawrence, Ewing, Hopewell Township, and most other towns	No dedicated ordinance located; confirm directly with the municipality

Princeton's story is the one worth understanding in detail, because it's the most consequential change in the county this year. On December 18, 2025, the council adopted Ordinance #2025-20 by unanimous vote. Councilman Leighton Newlin framed it around housing rather than tourism, saying "our job is to make sure Princeton remains a place where people can actually live, raise families, build roots." That principal-residence requirement is the whole ordinance in one sentence. A single-family or attached home can only be a short-term rental if the operator lives there, and in a two- or three-family building, only one unit the operator occupies qualifies. Investors who bought a Princeton property just to run it on Airbnb are watching a market close under them over the next three years, not open up.

Trenton is the closer read for anyone who wants to run a nightly rental business rather than share a spare room. Its ordinance was written to let short-term rentals continue as a normal category of use, though a unit loses eligibility if it's income-restricted housing, carries an open building or fire code violation, or has racked up three violations of the same kind within six months. Robbinsville sits at the other extreme, having decided in 2019 that the trade-off wasn't worth it at all. If your Mercer County property sits in a town that's landed somewhere between those two, the closest useful comparisons are what other New Jersey counties have done with the same state framework. The Camden County guide shows a county where the largest towns went restrictive the way Robbinsville did, while the Hudson County guide covers a much denser market with its own registration regimes worth benchmarking against.

Short-Term Rental Licensing Requirements in Mercer County

Assuming your town is one of the two with an actual process, Princeton's and Trenton's licensing systems look almost nothing alike, so it's worth walking through each on its own terms rather than assuming one maps onto the other.

Princeton's permit runs through the Office of Rental Housing Inspections via an online OpenGov portal. Initial registration and inspection cost $200, and renewal is $100 a year after that, with the permit valid for a single year at a time. An inspector has to physically walk the unit with the applicant present, typically taking 15 to 30 minutes, and there's no exemption for an owner-occupied property, even if you live there. Fail the inspection and you get an automatic reinspection window of 30 days, with extensions available on written request. Once you're approved, your permit number has to appear on every listing, you need 24/7 contact availability with a two-hour response window, and you're required to post an 8.5-by-11 placard inside the front door.

Trenton's registration process runs through the Department of Inspections instead, and it reads more like ordinary landlord paperwork than a specialized permit. Registration is annual, from January 1 through December 31, with no proration if you register partway through the year. There's no separate inspection just to register, though non-owner-occupied units still fall under the city's standard five-year rental inspection cycle. Once you're on the Short-Term Rental Registry, you get a registration number that's tied to both the unit and you specifically. Sell the property or bring on a new owner, and the new owner has to register fresh rather than inheriting your number.

Just make sure you check eligibility before you pay either fee, since neither city refunds it. Princeton's ordinance flatly excludes non-owner-occupied units once the three-year phase-out window closes, and Trenton's ordinance disqualifies units that are income-restricted, sit on a prohibited-buildings-style list of code violations, or have already accumulated repeat complaints. Everywhere else in the county, remember there's no license to apply for at all until you've confirmed your municipality runs one.

Required Documents for Mercer County Short-Term Rentals

Once you know which office you're dealing with, the paperwork itself is fairly predictable, even though Princeton and Trenton ask for genuinely different things.

Princeton's application is the more invasive of the two, by design, since it's built to verify that you live in the home you're registering. Gather these before you start the online application:

• Property details, including the tax map reference, a floor plan with measurements, and parking information.
• A New Jersey driver's license or state ID for the owner or long-term lessee.
• The front page of your last two years of federal 1040 returns, redacted, to help establish that this address is where you file from.
• Three months of bank statements, redacted, showing the same address.
• Proof of at least $500,000 in liability insurance.
• 24/7 contact information for someone who can respond within two hours.

Trenton's registration form asks for a different kind of detail, closer to a standard rental registry than a residency test:

• The owner's name and contact information.
• A local contact in Trenton, or a bordering town, if the owner lives elsewhere.
• A floor plan showing the exact number of sleeping rooms.
• Proof of property liability insurance for the full registration term.
• Any condominium bylaws that might restrict the unit's use.

You'll also need to keep a record of every renter's name and contact details for three years after each stay ends, which the city can request at any time.

Keep in mind that these lists are the ingredients, not a form you fill out once and forget. In Robbinsville, no document set unlocks anything, because the zoning code prohibits the use outright regardless of what paperwork you assemble. There, the only thing that changes the answer is a lease of 30 days or more, which takes the arrangement out of the short-term category entirely.

Mercer County Short-Term Rental Taxes

Say your town allows the stay and your paperwork clears. The moment money changes hands, tax attaches, and because state and municipal governments both take a piece, the layers don't sit at the same level or apply the same way everywhere. Let's take them one at a time.

State Taxes

The state layer is identical no matter which Mercer County town you're in: a taxable stay owes New Jersey Sales Tax of 6.625% plus a State Occupancy Fee of 5%, a combined 11.625% on the rent. The good part is who ends up handling it, since booking through Airbnb or Vrbo means the platform signs up to collect both taxes and pays them to the state for you, automatically, on stays of 89 nights or fewer. Book a guest directly, though, and if your unit counts as a "professionally managed unit," meaning you or whoever controls it offers two or more other New Jersey units for rent that year, you're the one who has to register, collect, and file it yourself.

Charge	Rate	Collected by
NJ Sales Tax	6.625%	Airbnb/Vrbo, or the host on a direct booking
State Occupancy Fee	5%	Airbnb/Vrbo, or the host on a direct booking
Municipal Occupancy Tax	Up to 3%, only where the town adopted it	Airbnb/Vrbo, or the host on a direct booking

County and Municipal Taxes

Mercer County itself levies no lodging tax of its own, the way a shore county like Cape May does. That's one less line to track when you're pricing a stay. What varies is the municipal piece, since New Jersey lets most towns adopt a Municipal Occupancy Tax of up to 3% on top of the state rate. Princeton has adopted it, extending its existing 3% occupancy tax to qualifying short-term stays. Trenton adopted its own version too, but set it lower, at 1%. Since this is the layer most likely to shift town by town, confirm your specific municipality's current rate with its finance office rather than assuming Princeton's number applies everywhere.

Tax Deductions and Write-Offs

On the other side of the ledger, short-term rental income is ordinary taxable income. The usual deductions apply against it, though: the platform's host fee, cleaning and supplies, insurance, a share of utilities, repairs, and depreciation on the furnished portion. Princeton's ordinance now requires exactly that arrangement, a room inside your own home. So you'll need to apportion most of those expenses between personal and rental use, and that split is fiddlier than it looks on a spreadsheet. Hold onto every receipt and hand the apportionment to an accountant who's dealt with a mixed-use return before.

New Jersey Wide Short-Term Rental Rules

Those municipal taxes and permits make more sense once you see the statewide frame they hang on, because a fair amount of what governs a Mercer County rental is New Jersey law rather than anything local, and a few pieces matter beyond what's already covered above.

Start with how narrow the tax itself is. New Jersey's framework only applies to a stay booked through a "transient space marketplace" like Airbnb or Vrbo, or to a professionally managed unit. So a direct booking from an owner with fewer than three total New Jersey units, made entirely outside a marketplace, isn't taxed under this regime at all, according to the state's own technical bulletin. Stays of 90 days or more are exempt too, and so are rentals a licensed New Jersey real estate broker handles start to finish, with no hotel-style services attached.

Separate from tax, a professionally managed unit has to file Form NJ-REG with the Division of Revenue and Enterprise Services at least 15 business days before renting, unless every booking runs through a marketplace that already collects the tax on your behalf. It's a one-time business registration rather than an annual license, so don't confuse it with anything Princeton or Trenton charges you locally. Our New Jersey statewide guide walks through NJ-REG and the rest of this framework in more depth if you're weighing a purchase outside Mercer County too.

New Jersey's Hotel and Multiple Dwelling Law is the other piece worth knowing, since it governs buildings of three or more units and pulls them into state inspection through the Department of Community Affairs' Bureau of Housing Inspection. If your plan involves a triplex or larger building rather than a single-family home or a room in your own house, be aware you may be adding that state inspection cycle on top of whatever your municipality already requires. Most legal Mercer County hosting lives in a single room inside an owner-occupied house, under Princeton's rules, and this generally won't reach that setup at all.

Does Mercer County Strictly Enforce STR Rules?

Given how differently these towns treat the underlying question, you might expect enforcement to be just as scattered, and in a sense it is, but each town that has a rule at all seems to mean it.

Trenton's penalty structure is the most explicit of the bunch, and it's built to escalate rather than sting once and stop. Offering an ineligible unit as a short-term rental draws $300 per violation per day, and each day of continued noncompliance counts as a fresh violation. Failing to register at all, or continuing to operate after the city suspends your registration, runs $100 per day on the same escalating basis. Since the fine compounds daily rather than resetting, a listing that stays up after a warning gets expensive fast, not gradually.

Princeton built a similarly steep structure into its new ordinance: fines up to $1,250 per day, with each day of a continuing violation treated separately, plus possible imprisonment or community service on top. That's a meaningful number for a town that's already requiring two years of tax returns and three months of bank statements just to get a permit. It tells you the borough intends to actually check who's operating, not issue permits as a formality.

Robbinsville's approach is different in kind rather than degree, since there's no permit to violate, only a use the zoning code prohibits outright. The township's own announcement of the ban came after a presentation from its Economic Development Advisory Commission. That suggests the council heard a specific case for the ban rather than adopting one reflexively, and towns that act on a specific complaint tend to keep watching for the behavior that triggered it. If you're in a Mercer County municipality without a dedicated ordinance, don't read that silence as safety. It usually means enforcement, if it happens, comes through general zoning or nuisance complaints rather than a purpose-built process, which can be slower to trigger but isn't any less real once a neighbor calls.

How to Start a Short-Term Rental Business in Mercer County

Taking all of that together, the order you work through these steps matters more than it looks, because the early ones tell you whether the later ones are worth your time at all.

1. Identify your exact municipality and find out whether it has a short-term rental ordinance. Mercer County has no countywide answer, so knowing that Trenton allows registration tells you nothing about Robbinsville or Hamilton Township.
2. If your town bans the use outright, stop here. No document, insurance policy, or inspection buys around a zoning prohibition, and Robbinsville is currently in that category.
3. If your town has a permit or registration process, confirm you're eligible before you pay anything. Princeton requires owner-occupancy and excludes non-owner units after the phase-out; Trenton excludes income-restricted units and properties with open violations.
4. Assemble the specific document set your town asks for. Princeton wants tax returns, bank statements, and $500,000 in liability coverage; Trenton wants a floor plan, insurance proof, and a local emergency contact.
5. Apply, pay the fee, and schedule the inspection if one's required. Princeton inspects every unit regardless of ownership status; Trenton's five-year cycle applies mainly to non-owner-occupied units.
6. Register for state tax collection if you're booking outside a marketplace. File Form NJ-REG if your rental counts as professionally managed, and confirm whether Airbnb or Vrbo is already collecting the state and municipal taxes for you.
7. Post what your town requires and keep the records it asks for. Princeton's placard and two-year ledger, Trenton's three-year renter records, and either city's registration number on every listing.
8. If your town has no dedicated ordinance, call before you list, not after. Confirm with the municipal zoning office what general rules apply, since "no ordinance" isn't the same thing as "no rules."

Who to Contact in Mercer County about Short-Term Rental Regulations and Zoning

Whichever step you get stuck on, the office you need is almost always your own municipality, not the county, so knowing which one owns your question saves you a run-around.

Mercer County Planning Department (for county subdivision and site-plan review, not short-term rental permits):

• Address: McDade Administration Building, 640 South Broad Street, Room 411, Trenton, NJ 08611
• Phone: 609-989-6545
• Note: the department's own contact page covers land development applications and planning-board matters, not Airbnb rules, so it will refer you back to your town.

Princeton Office of Rental Housing Inspections (for the short-term rental permit itself):

• Address: 1 Monument Drive, Princeton, NJ 08540
• Phone: 609-454-4756
• Email: [email protected]
• Hours: Monday through Friday, 9 a.m. to 5 p.m.

Trenton Division of Housing Inspections (for the Absentee Owner Program and short-term rental registration):

• Address: 319 East State Street, Trenton, NJ 08608
• Phone: 609-989-3563

Robbinsville Township (for zoning questions, given the current outright ban):

• Address: 2298 Route 33, Robbinsville, NJ 08691
• Phone: 609-259-3600
• Hours: 8:30 a.m. to 4:30 p.m., Monday through Friday

Hamilton Township Housing Inspection & Landlord Compliance Office (for general rental change-of-occupancy questions, since no short-term-specific office exists there):

• Address: 2090 Greenwood Avenue, Room 302, Hamilton, NJ 08609
• Phone: 609-890-3665

New Jersey Division of Taxation (for Sales Tax, the State Occupancy Fee, and Form NJ-REG):

• Online: the Transient Accommodations FAQ

What Do Airbnb Hosts in Mercer County on Reddit and Bigger Pockets Think about Local Regulations?

Those official contacts tell you what the rules are; the investor forums tell you how people feel about them, and in Mercer County the mood tracks the town-by-town split pretty closely. What follows is my read of the recurring themes rather than any kind of survey, so do weigh it accordingly.

• Princeton draws the most active complaints, and they're mostly about the owner-occupancy rule, not the fee. Investors who bought a Princeton property specifically to run it as a whole-home Airbnb are describing a three-year clock they didn't expect, and the recurring advice is to sell or convert to a long-term rental well before the phase-out actually bites, rather than waiting to see if it gets extended.
• Trenton gets talked about as the accessible option in the county, with the caveat that it's still Trenton. Hosts who register there describe the process itself as manageable, closer to ordinary landlord paperwork than a specialized hurdle, while flagging that demand and nightly rates lag the county's more residential towns.
• Hosts in towns without a dedicated ordinance describe genuine uncertainty, not comfort. The recurring theme on BiggerPockets threads about Hamilton Township and similar towns isn't "it's unregulated so it's fine," it's people asking each other whether the silence means anything, which is exactly the kind of question a phone call to the zoning office answers better than a forum ever will.
• Robbinsville barely comes up at all, which tracks with a flat ban leaving nothing to discuss beyond confirming it's still in effect.

Take the Princeton point seriously if you're holding a non-owner-occupied unit there, since the phase-out clock is already running. And if you're still deciding where in New Jersey to put a short-term rental dollar in the first place, pull up the New Jersey market data before you commit to a specific Mercer County address. It shows what comparable units are earning across the state, not just what one town will let you do.

Frequently Asked Questions

Can you legally run an Airbnb in Mercer County, New Jersey in 2026?

It depends entirely on your municipality, since Mercer County has no countywide rule. Princeton allows it for owner-occupants under a new permit system, Trenton allows it with annual registration, and Robbinsville bans it outright under a 2019 ordinance. Most other Mercer County towns, including Hamilton Township, have no dedicated short-term rental ordinance, which means general zoning rules apply instead. Always confirm with your specific town's zoning office before listing a property.

Does Mercer County require a short-term rental permit or license?

The county itself doesn't issue one. Licensing, where it exists, is entirely municipal. Princeton requires a $200 initial permit with $100 annual renewals and restricts hosting to owner-occupants. Trenton requires annual registration for $300 initially and $150 to renew, with no owner-occupancy requirement. In towns without a dedicated ordinance, there's no short-term-rental-specific license to apply for, though general rental registration rules may still apply.

What taxes apply to a short-term rental in Mercer County?

A taxable stay owes New Jersey Sales Tax of 6.625% plus a State Occupancy Fee of 5%, for a combined 11.625% on the rent. A municipality may add its own occupancy tax of up to 3%; Princeton charges 3% and Trenton charges 1%. Mercer County itself levies no lodging tax. When you book through Airbnb or Vrbo, the platform generally collects and remits the state taxes automatically for stays of 89 nights or fewer.

Is Hamilton Township, Mercer County's largest town, banning short-term rentals?

No, and this is worth clearing up directly, since search results sometimes attribute a short-term rental ban to "Hamilton Township, NJ" that belongs to a different Hamilton Township in Atlantic County. Mercer County's Hamilton Township has no dedicated short-term-rental chapter in its code as of this research pass. That means general zoning and the township's ordinary rental change-of-occupancy process apply, not a specific ban or a specific permit, so confirm directly with the township before assuming either.

Can I rent my Mercer County home for 30 days or more instead?

Yes, and in a town like Robbinsville that's the only legal nightly-adjacent option available. A stay of 30 consecutive days or longer falls outside every municipal short-term rental ordinance in the county, and stays of 90 days or more are exempt from the state transient taxes as well. That moves the arrangement into ordinary landlord-tenant law, where New Jersey's tenant protections are strong, so use a proper lease and understand you're taking on a tenant rather than hosting a guest.

Last verified: July 2026. Every ordinance, tax rate, state law, and contact detail in this guide links to or comes from its official source.