Union City, California Short-Term Rental Regulations: A 2026 Guide For Airbnb Hosts

Do you own a place in Union City and you're weighing whether to put it on Airbnb or Vrbo? Well, the good news is that nobody's going to hand you a 30-page permit application, because Union City has never written a short-term rental ordinance at all. There's no registry, no cap on nights, no primary-residence rule, and no annual STR permit to renew. Searching the municipal code for the phrase "short-term rental" turns up bicycle parking standards and one line in the business tax schedule, and that's about it.

Unfortunately, the absence of an ordinance isn't the same thing as permission. Union City sits in Alameda County, California, and its zoning code works off a closed list: § 18.32.020 of the Union City Municipal Code opens by saying that "a use that is not listed here or in Section 18.32.030 is not a permitted use." The only lodging-style use on that list for the R and RS residential districts is "room, room and board, or boardinghouses for not more than two paying guests". Two. So the legal shape of a Union City short-term rental looks a lot more like a spare room than a whole house on Airbnb, and the city's own short-term rental application reprints that exact sentence to make sure applicants have read it.

So let's walk through what it actually takes to do this properly: which use the zoning code will and won't bless, the business license and tax registrations you still owe even when Airbnb handles the money, the three separate charges that attach to a stay in 2026, how enforcement really works in a city with no STR program, and who to call at City Hall when something doesn't fit. Every figure below comes from Union City's or California's own pages, checked in July 2026, and where a source contradicts another one I've said so instead of picking a winner. Assuming you're weighing this address against markets where an entire unit can legally go on a nightly platform, run both through BNBCalc before you buy anything.

What are short term rental (Airbnb, VRBO) regulations in Union City,California?

That closed-list rule is where everything starts, so it's worth understanding how a city with no STR chapter still ends up regulating one.

Most California cities that allow short-term rentals wrote a dedicated ordinance for them, usually somewhere in the 2015 to 2022 window, with a permit number, a night cap and a good-neighbor policy. Union City didn't. A full-text search of the Union City Municipal Code, current through legislation adopted in June 2026, returns no short-term rental chapter, no STR permit, and no registry. What it returns instead are bicycle parking standards, an emergency shelter definition, overnight animal boarding at veterinary offices, and Category 4 of the business tax. That's the whole picture.

Zoning fills the gap, and it fills it narrowly. Three provisions do most of the work:

• § 18.32.020 is a closed list. If a use isn't written into it or into the conditional use section, it isn't permitted in a residential district. Whole-home transient lodging isn't written into it.
• § 18.32.020(E) is the one that touches you. "Room, room and board, or boardinghouses for not more than two paying guests in the R and RS districts; lodging rooming houses in the RM 1500 district." That two-guest ceiling is the operative number, and it applies to the guests, not the bookings.
• § 18.32.030 adds a conditional route. Lodging rooming houses are permitted in residential districts upon the granting of a use permit, which means a discretionary application to the Planning Division rather than an over-the-counter approval.

Hotels and motels do exist in the code, of course. They just live somewhere else. The commercial district use table at § 18.36.020 lists "Lodging (hotel and motel)" as a permitted use in the CVR district and a conditional use elsewhere in the C districts, which is the city telling you plainly where transient lodging belongs. Your house on a residential street is not in a C district.

Accessory dwelling units get a flat prohibition, and it's the least ambiguous sentence in the whole code. Chapter 18.34, rewritten by Ordinance 2025-002 on 25 March 2025, says under the heading "Short-Term Rental Limitation" that "ADUs shall not be rented for a term of less than 30 days." No use permit gets around that one, since it mirrors the state floor in Government Code § 66323(e). Plenty of Bay Area owners built an ADU in the last five years expecting to run it nightly, so do check your permit paperwork before you assume otherwise.

One more definition matters, because it decides when the tax clock starts. Chapter 3.18 of the code defines a "transient" as anyone occupying space "for a period of thirty consecutive calendar days or less, counting portions of calendar days as full days." Cross 30 days and you're outside the transient regime entirely. Stay under it and you're a hotel operator in the eyes of the Finance Director, whatever the listing calls itself.

Starting a Short Term Rental Business in Union City

Which brings us to the uncomfortable part, because that two-guest ceiling rules out the business model most people arrive with.

Unfortunately for anyone picturing a furnished three-bedroom off Alvarado-Niles rented whole at nightly rates, that use isn't on the residential permitted-use list, and no fee buys it. Union City is a commuter city of roughly 70,000 people between Fremont and Hayward, with a BART station and very little tourism, so it was never going to be a vacation-rental town anyway. What the code leaves you is genuinely a room-share, and the economics of a spare bedroom are a different business from the economics of a whole unit.

Here's what remains open, in rough order of how realistic each one is:

• Renting rooms in your own home to at most two paying guests. This is the mainstream path and the one the city's forms are built around. Two paying guests is the ceiling in the R and RS districts, and it doesn't reset per booking.
• A lodging rooming house in the RM 1500 district, which § 18.32.020(E) permits outright. That's a multifamily zone, so it applies to a small slice of the city's housing stock rather than to a typical single-family lot.
• A lodging rooming house elsewhere in a residential district with a use permit under § 18.32.030. Discretionary approvals take months, cost real money in application fees, and can be denied, so treat this as a project rather than a weekend plan.
• A hotel or motel use in a commercial district. Legal, listed, and completely out of scale for an individual owner.
• Stays of 30 nights or longer, which fall outside Chapter 3.18 altogether and outside the transient definition. This is where most Union City inventory that can't work nightly ends up.

Be aware that the mid-term pivot carries its own local rulebook. Once a tenant resides in a unit for more than 30 consecutive days, § 5.50.030 pulls the unit into Union City's Residential Landlord and Tenant Relations Ordinance, and that section also forbids terminating a tenancy or making someone check out and re-register before 30 days "if a purpose is to avoid the effects of this chapter." So the 29-night rolling booking that some operators use elsewhere is specifically anticipated here. The city's Rent Review Ordinance sits alongside it, with a $10 per rental unit per year fee in the current fee schedule.

Two private restrictions can end the conversation before the city ever does. Civil Code § 4741(c) lets a homeowners association prohibit "transient or short-term rental" of 30 days or less even though it can't ban longer rentals, which covers a lot of the newer townhome and condo stock along Decoto Road. And if you rent rather than own, your lease almost certainly settles it. Make sure you read both documents before you spend anything on furniture.

Short Term Rental Licensing Requirement in Union City

Assuming your situation still fits inside that two-guest box and you're able to move ahead, there's still paperwork, and it runs through the Finance Department rather than through any short-term rental office.

There's no STR permit in Union City, so what you're actually getting is three separate registrations that happen to travel together. A business license comes first. Under Title 5 of the code, the city requires a business license for "all businesses, trades, professions, callings, and occupations operating in Union City," and it says explicitly that this covers home-based businesses. Before Finance will issue it, the Planning Division has to sign off on a zoning compliance review, which is where the § 18.32.020 question gets asked and answered for your specific address.

Second comes the short-term rental filing itself. The city publishes a standalone Short-Term Rental Application, revised 4 December 2024, plus a shorter Short-Term Rental Supplemental Form that attaches to the business license application. Both carry the same declaration under penalty of perjury, and both reprint the two-paying-guest sentence from Chapter 18.32 directly above the signature line. Unsigned applications don't get processed at all.

Third is the transient occupancy tax registration. § 3.18.050 requires every operator renting occupancy to transients to register within 30 days of commencing business and to obtain a Transient Occupancy Registration Certificate, "to be at all times posted in a conspicuous place on the premises." Read the certificate's own wording carefully, because it settles a question people get wrong: it "does not authorize any person to conduct any unlawful business or to conduct any lawful business in an unlawful manner," and it flatly states "this certificate does not constitute a permit." Holding a TOT certificate is not the city agreeing that your use is allowed.

What it costs is modest, at least in fees:

Charge	Amount	Notes
Zoning Compliance Review, residential districts	$61 in FY 2026-27	$59 in FY 2025-26, adjusted 2.5% for CPI
Business tax, Category 4 minimum	$154 per year	Minimum annual registration tax
Business tax, Category 4 rate	0.00225 x gross receipts	First $25,000 of gross receipts is exempt from the rate
State disability access fee	$4	SB 1186 / AB 1379, added to applications and renewals

Those fee figures come from the city's adopted Master Fee Schedule for FY 2026-27 and from the business tax chapter. Certificates run no more than 12 months from issuance or renewal, business taxes are delinquent 30 days after they're due, and the late penalty is 10% of the tax on the first day of delinquency plus another 10% each subsequent month, capped at 50%. Remember that the certificate expires on your own anniversary month rather than on a citywide date, so diarize it.

Required Documents for Union City Short Term Rentals

Since the application carries a penalty-of-perjury declaration, it's worth getting the file complete before you submit rather than after. The Short-Term Rental Application asks for the following, and every field marked required on the form is required in practice:

• Primary contact details for the applicant and a second contact, each with address, phone and email.
• A local emergency contact. The form says to complete this always and that the contact "should be available at any time." This is Union City's version of the 24/7 local-contact rule other cities put in an ordinance.
• Property owner name and the month and year you began renting in Union City.
• Ownership type and a tax identifier. A federal employer ID number if you're a corporation or LLC, or a driver's license, government-issued ID or individual taxpayer ID number if you're a sole proprietor, partnership, trust or estate.
• Every Union City rental address you own, with the number of units at each, plus the total number of rental units you own in the city.
• Property manager details, where one is involved.
• A signature, printed name, title and date. Unsigned forms are returned.

Alongside that you'll need the business license application itself, which asks for estimated annual gross receipts, your seller's permit number where you hold one, ownership structure, business start date and the names of all owners, partners or corporate officers. The zoning compliance review runs in parallel through Planning. Keep in mind that California's AB 2184 lets you supply a separate service-of-process address instead of publishing your home address, and the form tells you to raise that with staff at the time of application rather than afterwards.

Union City Short Term Rental Taxes

Assuming you clear the license and are able to take a booking, there's still tax, and three separate charges can attach to a single Union City stay. Two of them go to the city and one goes to the state, which is why the filing calendars don't line up.

Charge	Rate	Collected by
Transient occupancy tax	13.86% for FY 2026-27	City of Union City (Airbnb remits for Airbnb bookings)
Business tax, Category 4	0.00225 x gross receipts, $154 minimum	City of Union City
California Tourism Assessment	Accommodations rate, self-assessed	California Office of Tourism
State income tax on profit	Ordinary rates	Franchise Tax Board

The transient occupancy tax is the big one, and its arithmetic is unusual. § 3.18.025 sets the rate "at eight and one half percent of the daily room rate, to be annually adjusted according to the consumer price index," so the number in the code is not the number you charge. The city publishes the current figure each fiscal year on its Taxes and Fees page: 13.54% for FY 2023-24, then 13.86% for FY 2024-25, FY 2025-26 and FY 2026-27, covering hotel activity from 1 July 2026 to 30 June 2027. Because the rate moves with CPI, check that page each July rather than carrying last year's number forward.

Here's a live discrepancy worth knowing about. Airbnb's California collection list still states that guests booking a Union City listing pay a transient occupancy tax of "13.54% of the listing price including any cleaning fees, for reservations 30 nights and shorter," which is the FY 2023-24 rate. Airbnb's page links straight to the city page that says 13.86%. I couldn't find any city statement reconciling the two, so treat the city's own figure as authoritative and don't be surprised if your payout statements show something different.

Who collects it depends entirely on where the booking came from. The city's page records that "on August 1, 2017 Airbnb began collecting the Transient Occupancy Tax on behalf of their hosts" and remitting monthly under a voluntary collection agreement. If every reservation comes through Airbnb, you still have to register with the TOT program, but you don't file TOT returns. Book through any other platform, or directly with a guest, and you register, collect and remit yourself. The city's own handoff document for Airbnb hosts makes the limit of that arrangement explicit: Airbnb steps into the host's shoes "solely for the purpose of collecting and remitting" and not for "short-term rental permitting, zoning, health and safety requirements."

Filing yourself means quarterly returns to the Finance Director, due on the last day of the month after each quarter closes, so 31 October, 31 January, 30 April and 31 July. Miss it and § 3.18.070 adds a 10% penalty immediately, a second 10% if you're still delinquent 30 days later, 25% on top where the Finance Director finds fraud, plus interest at half a percent per month. Watch out for the record-keeping rule too, since § 3.18.100 requires every operator to keep the underlying records for three years and lets the Finance Director inspect them at any reasonable time.

The business tax is the piece that changed most recently, and it changed in a way that names you directly. Union City voters passed Measure QQ on 5 November 2024 with 81.62% support, the county certified it on 5 December 2024, and the new structure took effect on 1 April 2025. Ordinance 930-24, adopted 10 December 2024, rebuilt the business tax on gross receipts, and Category 4 reads "Rental (commercial and residential), self-storage, hotels, motels and short-term rentals" at 0.00225 of gross receipts with a $154 minimum annual tax. The first $25,000 of annual gross receipts escapes the rate, though the minimum still applies, and both the minimum and that threshold move each fiscal year with the San Francisco, Oakland and Hayward CPI.

Above the city, California adds two layers and no occupancy tax of its own. Revenue and Taxation Code § 7280 merely authorizes cities and counties to tax stays of 30 days or less, with no state cap, which is why Union City's rate is a local decision. Lodging revenue is assessable under the California Tourism Assessment in the Accommodations category, with revenue from stays of 31 or more continuous days by the same person excluded, and no platform remits that for you. And rental profit is ordinary taxable income to the Franchise Tax Board, residents on everything and nonresidents on California-source income.

Union City wide Short Term Rental Rules

Those tax obligations apply to every address in the city, and so does a second tier of rules that has nothing to do with Union City at all.

California leaves short-term rental regulation to cities and counties almost entirely. There's no statewide STR permit, no state registry and no state occupancy tax, and no statute broadly preempts what a city like Union City decides to do under its police power. What the state does instead is set boundaries at the edges, and four of them reach a Union City host directly:

• Fine ceilings. Government Code § 36900 governs what a city may charge for an infraction, and for short-term rental ordinance violations specifically it caps fines at $1,500, then $3,000 for a second within a year, then $5,000, with the elevated tiers reserved for violations that threaten health or safety and a hardship waiver process required. Union City's own general penalty chapter points straight at that section.
• HOA authority. Civil Code § 4741(c) permits a common interest development to ban rentals of 30 days or less outright, and a great deal of Union City's newer inventory sits inside one.
• The ADU floor. Government Code § 66323(e) requires that ADU rentals run longer than 30 days, which is where Chapter 18.34's local prohibition comes from.
• Platform and pricing duties. Business and Professions Code § 17568.6 requires advertised nightly rates to include every mandatory fee except government taxes, with the full total shown before booking. A companion section adds cleaning-task disclosure duties, and § 22592 obliges platforms to warn hosts that listing may breach their lease and that their insurance may not cover the use.

One newer state law is worth tracking, even though it doesn't bite here yet. The Short-Term Rental Facilitator Act of 2025, at Government Code §§ 50990 to 50996, took effect on 1 January 2026 and makes platforms report each rental's physical address and display local license numbers, but only where a local agency has adopted an ordinance opting into it. Union City has adopted none, and the code search confirms it, so nothing in that statute currently obliges Airbnb to hand Union City an address list. Should the Council ever write an STR ordinance, that reporting machinery is sitting there waiting.

The wider California picture is worth having in view if you're deciding between markets rather than defending one address. Our California statewide guide maps how differently cities treat this, while San Francisco's rules show what a registered, primary-residence regime looks like up close and the San Mateo County guide covers the peninsula on the other side of the bay.

Does Union City strictly enforce STR rules?

That absence of an STR ordinance shapes enforcement too, and not in the direction most hosts hope.

There's no short-term rental inspector in Union City, no annual compliance sweep that I could find any record of, and no published citation data. The city has never stood up an STR program, so there's nothing to staff. What that means in practice is that enforcement is complaint-driven and lands on whichever department the complaint reaches: Code Enforcement for a land-use question, Finance for an unregistered business or unpaid tax, Planning for a zoning determination.

The penalty framework behind them is broader than a typical STR ordinance, though, which is the part people miss. Under § 1.16.010, any violation of the Union City code may be prosecuted as a criminal offense, and unless a provision expressly says otherwise a violation is a misdemeanor, punishable by a fine of up to $1,000, up to six months in jail, or both. The prosecutor may charge it as an infraction instead, and after three convictions on the same section later violations can be bumped back up to misdemeanors. Section 1.16.010(D) is the sharp one: each person "is guilty of a separate offense for each and every day" a violation continues. That's not a one-time fine, then. It accrues nightly, which is exactly how a marginal listing turns into a serious number.

Section 1.16.020 adds that any condition existing in violation of a city ordinance is a public nuisance and may be abated, with each day treated as a new offense there as well. And § 1.16.030 lets any city official charged with enforcing the ordinance in question issue an infraction citation, not only police officers. On the tax side, § 3.18.080 gives the Finance Director power to estimate what you owe from whatever facts can be gathered and assess it against you, with ten days to request a hearing and fifteen days to appeal to the City Council after that. Misrepresenting a material fact to obtain a business tax certificate is separately an infraction under Ordinance 930-24.

Two structural points follow from all this. First, a live listing is its own evidence. Because there's no registry, there's no permit number that makes a listing look legitimate, and a public Airbnb page advertising a whole house in an R district describes a use the code doesn't list. Second, the tax trail is already flowing. Airbnb has been remitting Union City's transient occupancy tax since 2017, so the city knows the aggregate, and a host who registered for TOT has told the city an address. Quiet is not the same as invisible.

Honestly, my read is that a two-guest room rental with a business license, a TOT registration and no complaints from the street is a low-risk operation in Union City. A whole-house nightly listing in a residential district is a different animal: unpermitted as a use, exposed to a per-day penalty, and dependent on nobody ever calling 510.675.5315.

How to Start a Short Term Rental Business in Union City

Given all that, the order you do things in matters more than it looks, because the early steps tell you whether the later ones are worth the money.

1. Find your zoning district first. R, RS, RM and the commercial districts each answer this question differently, and the Planning Division at 510.675.5379 will confirm the designation for a specific address. Nothing else is worth doing until you know.
2. Read your CC&Rs, HOA rules or lease. Civil Code § 4741(c) lets an association ban stays of 30 days or less outright, and a lease clause ends it just as fast.
3. Design the stay so it's actually a listed use. In R and RS that means renting rooms to no more than two paying guests at a time. If the plan involves a whole house, an ADU, or a third guest, stop and rethink it here rather than after you've furnished the place.
4. Get the zoning compliance review. It's $61 for a residential district in FY 2026-27, and it's the step where the city says yes or no to your use in writing.
5. File the business license application plus the short-term rental forms. Both the standalone application and the supplemental form carry a penalty-of-perjury declaration, and both need a local emergency contact who's reachable at any time.
6. Register for transient occupancy tax and post the certificate. § 3.18.050 gives you 30 days from commencing business, and the certificate has to be displayed conspicuously on the premises.
7. Work out who's collecting the tax. Airbnb remits it for Airbnb bookings; every other channel is yours to collect and remit quarterly on 31 October, 31 January, 30 April and 31 July.
8. Set up records on day one. Three years of rent and tax records is the statutory minimum, and the Finance Director can ask to inspect them at any reasonable time.
9. Diarize renewals. The business tax certificate runs no more than 12 months, the TOT rate is republished each July, and the business tax minimums move with CPI each fiscal year.

Before any of that, run the numbers on what a compliant two-guest room actually clears against what the same capital does elsewhere. Union City's own listing economics sit inside a much larger picture, and the California market is the place to compare the revenue side before you commit to the compliance side.

Who to contact in Union City about Short Term Rental Regulations and Zoning?

Whichever of those steps you get stuck on, three counters at City Hall handle almost all of it, and knowing which one owns your question saves a lot of transferred calls.

City Hall is at 34009 Alvarado-Niles Road, Union City, CA 94587. Public hours are Monday to Thursday, 9:00 AM to 5:00 PM, and Friday 9:00 AM to 12:00 PM, with the city closed every other Friday. The general line is 510.471.3232, and all of this comes from the city's Contact Us page.

Zoning, permitted uses and the compliance review

The Planning Division, inside the Economic and Community Development Department, answers whether your use is permitted at your address and runs the zoning compliance review for business licenses.

• Phone: 510.675.5379
• Counter hours: Monday to Thursday, 9:00 AM to 2:00 PM, in person or virtual
• Phone and email hours: Monday to Thursday, 8:00 AM to 6:00 PM, and alternating Fridays 8:00 AM to 5:00 PM
• Appointments: the Planning page takes bookings for 25-minute meetings and asks you to name the Union City project address in advance
• Senior Planner: Mayank Patel, 510.675.5426
• Department director: Carmela Campbell, Economic and Community Development Director, 510.675.5316

Business license, short-term rental forms and transient occupancy tax

The Finance Department, Revenue Division issues the business license, takes the short-term rental application and administers the TOT.

• Address: 34009 Alvarado-Niles Road, Union City, CA 94587
• Phone: 510.675.5312 · Fax: 510.489.5074
• Email: [email protected]
• Revenue Manager: Rahnni Le, 510.675.5398, [email protected]
• Finance Director: Chu Thai, 510.675.5338
• TOT payments by mail: City of Union City, Attn: ASD Cashier (TOT Payment), 34009 Alvarado-Niles Road, Union City, CA 94587
• Forms and current rates: the Taxes and Fees page carries the remittance form for the current fiscal year

Complaints, violations and everything else

• Code Enforcement: 510.675.5315. This is the number a neighbor dials about a listing, so it's worth knowing in both directions.
• Building Division: 510.675.5313, for occupancy and construction questions
• Police non-emergency: 510.471.1365, for noise and parking at 2 AM

State-level questions

Anything about statewide rules sits outside City Hall. CalGold, run by the Governor's Office of Business and Economic Development, lists the permits a given address needs across every agency, and the Franchise Tax Board's rental income page covers the state income tax side.

What do Airbnb hosts in Union City on Reddit and Bigger Pockets think about local regulations?

Those phone numbers answer what the rules are. What hosts make of them is a different question, and a harder one to source honestly here.

Union City generates almost no public host discussion, which is itself informative. It's a commuter city with a BART station, not a destination, so the investor forums that argue endlessly about Palm Springs or Big Bear have very little to say about it. Reddit blocks our automated access and its platform terms don't permit the commercial data use this would require, so nothing below is a claim about what any specific thread says. What follows is my read of the position rather than a survey, and do weigh it accordingly.

• The confusion is predictable, and it's about silence. A city with no STR ordinance reads to a lot of owners as a city with no STR rules. That inference is wrong here, because Union City's zoning code is a closed list rather than a permissive one, and the two-guest sentence in § 18.32.020(E) is doing the work an ordinance would do elsewhere.
• Third-party regulation trackers get Union City wrong constantly, often by describing a permit process the city has never had, and sometimes by mixing it up with Union City, New Jersey. When a summary quotes an ordinance number, check that number against the city's own code before you rely on it.
• The tax side is where hosts actually get tripped up. Airbnb remitting the occupancy tax leads people to think they're fully registered, when the city's own page says Airbnb hosts must still register with the TOT program and hold a business license.
• The realistic conversation is about mid-term rentals. With a two-guest ceiling on nightly stays and a large commuter and travel-nurse population nearby, 30-plus-night furnished rentals are the version of this business that scales in Union City, subject to the landlord and tenant ordinances that attach at exactly that point.

Nothing suggests a change is coming, either. No STR ordinance has appeared in the code through June 2026, and the city hasn't opted into the state's platform-reporting framework. So plan around the rules as they are rather than around the ordinance Union City hasn't written.

Frequently Asked Questions

Can you run an Airbnb in Union City, California in 2026?

Only in a limited form. Union City has no short-term rental ordinance, and its zoning code is a closed list of permitted uses. In the R and RS residential districts the only lodging-style use permitted is a room, room and board, or boardinghouse for no more than two paying guests, so a whole-home nightly listing isn't a listed use. Accessory dwelling units cannot be rented for less than 30 days at all. Hosts still need a business license and a transient occupancy tax registration.

How much is the hotel tax on a Union City short-term rental?

Union City's transient occupancy tax is 13.86% for fiscal year 2026-27, covering stays from 1 July 2026 to 30 June 2027. The municipal code sets the base rate at 8.5% and adjusts it annually for the consumer price index, so the published rate changes each July. Airbnb has collected and remitted the tax for Airbnb bookings since August 2017. Bookings through any other platform, or direct with a guest, are the host's own to collect and remit quarterly.

Do you need a permit for a short-term rental in Union City?

There's no short-term rental permit, because there's no short-term rental ordinance. What you need instead is a Union City business license, which requires a zoning compliance review from the Planning Division first, plus a short-term rental application filed with the Finance Department's Revenue Division and a transient occupancy tax registration certificate posted on the premises. That certificate is not a permit, and the code says so on the certificate itself.

What is the penalty for an illegal short-term rental in Union City?

Under the city's general penalty chapter, any code violation may be prosecuted criminally and is a misdemeanor unless a provision says otherwise, carrying up to $1,000, up to six months in jail, or both. A prosecutor may charge it as an infraction instead, with fines set by California Government Code section 36900. Each day a violation continues is a separate offense, so exposure compounds nightly rather than arriving as a single ticket.

Can you rent an ADU in Union City on Airbnb?

No. Union City's accessory dwelling unit chapter, rewritten in March 2025, states that ADUs shall not be rented for a term of less than 30 days. That local rule tracks California Government Code section 66323(e), which requires ADU rentals approved under it to run longer than 30 days, so no local approval can override it. Renting the ADU for 30 nights or more is permitted, and it falls under ordinary landlord and tenant rules rather than the transient occupancy regime.

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