A developer named Ramtin Ray Nosrati put a spec mansion on the market this month on Donhill Drive, asking $35 million. The listing carries a Beverly Hills mailing address and the zip code every real estate agent in the country recognizes on sight. But the property sits inside the municipal boundaries of the City of Los Angeles, not the incorporated city of Beverly Hills, and that single fact changes the deal by close to two million dollars.
If the home sells at its asking price, the transaction lands in the top bracket of Los Angeles's Measure ULA transfer tax, which currently runs 5.5 percent on sales of $10.9 million or more. Hoodline estimates that, on a $35 million sale, the bill comes to roughly $1.9 million, owed to nobody who lives a quarter mile away inside the actual city of Beverly Hills. A neighboring estate with the same view, the same zip code, and the same 90210 return address would owe none of it.
This is not a quirk that affects one listing on one street. It is the defining fact of comparing anything labeled "Beverly Hills" right now, and most buyers researching the market never encounter it until an escrow officer explains it to them.
Two Cities, One Zip Code
Beverly Hills was incorporated in 1914, and its original northern border sat roughly a mile north of Sunset Boulevard. Everything north of that line, climbing into the Santa Monica Mountains toward Mulholland Drive, stayed part of Los Angeles. For decades that hillside land was rural and largely unnamed. In the 1920s the federal government routed its mail through the Beverly Hills post office anyway, simply because that was the nearest postal facility. When ZIP codes arrived nationally in 1963, the whole area, city and hillside alike, was folded into 90210.
The result is a zip code that has never matched a city boundary. Real estate agents and title companies call the hillside section Beverly Hills Post Office, or BHPO. It stretches from a few blocks above Sunset up to Mulholland, taking in enclaves like Beverly Park, Mulholland Estates, The Summit, Beverly Ridge Estates, Benedict Canyon, and Coldwater Canyon. Every one of those addresses reads "Beverly Hills, CA 90210." None of them are inside the city of Beverly Hills. Homeowners there rely on the Los Angeles Police and Fire Departments, not Beverly Hills Police or Fire, and their children attend schools zoned through the Los Angeles Unified School District rather than Beverly Hills Unified.
That jurisdictional split was a matter of which police department showed up and which school a child attended for most of the twentieth century. Since April 2023, when Los Angeles voters approved Measure ULA, it has also become a matter of transfer tax exposure that can run into seven figures on a single sale.
| Beverly Hills Proper | Beverly Hills Post Office (BHPO) | |
|---|---|---|
| Governing city | City of Beverly Hills | City of Los Angeles |
| Measure ULA exposure | Exempt | 4% on $5.4M–$10.9M; 5.5% above $10.9M |
| Police and fire | Beverly Hills PD and Fire | LAPD and LAFD |
| Public school district | Beverly Hills Unified | Los Angeles Unified |
| Representative enclaves | The Flats, Trousdale Estates, Gateway | Beverly Park, Mulholland Estates, Benedict Canyon |
The Bill Nobody Sees Until Escrow
Measure ULA applies only within the City of Los Angeles, according to the city's own Office of Finance. Independent municipalities carved out of the county, including Beverly Hills, Santa Monica, West Hollywood, and Culver City, are outside its reach entirely. For transactions closing after June 30, 2026, the current thresholds are a 4 percent tax on sales between $5.4 million and $10.9 million, stepping up to 5.5 percent above that.
None of that math touches a sale inside Beverly Hills proper. The city's only transfer levy is the standard countywide documentary transfer tax of, the same fee that applies to any property sold anywhere in Los Angeles County. The identical sale a few blocks north in BHPO, still carrying a 90210 return address, is subject to ULA.
Economists do not fully agree on how much this has slowed the luxury market on the Los Angeles side of the line. A University of California, Los Angeles analysis found the tax reduced the odds of a property selling above the threshold by as much as 55 percent, while a separate Cato Institute study released in December 2025 put the drop in eligible transaction volume closer to 38 percent. The estimates diverge, but the direction does not. Since the tax took effect, the city has collected more than a billion dollars for affordable housing funding as of January 2026, and a statewide ballot measure backed by taxpayer advocacy groups is now aimed at the November 2026 election, so the rules themselves may not be settled for long.
Trousdale Estates and the City Boundary
The instinct to structure a deal around a city boundary is not new to this decade. In 1955, developer Paul Trousdale bought 410 acres of former Doheny Ranch land above Sunset Boulevard for roughly $6 million, financed in part with money from Teamsters pension funds. Part of the deal required him to pay Beverly Hills an additional $400,000 to have the land formally annexed into the city rather than left as part of Los Angeles. The planned lots would sit inside actual Beverly Hills city limits, where a Beverly Hills address carried more weight than a hillside parcel governed by Los Angeles ever could.
Trousdale subdivided the land into 535 lots and built the only development he ever put his own name on. Trousdale Estates is protected today by a 1987 city ordinance that caps roof height at 14 feet and restricts building pads, which is why the mid-century architecture up there still reads the way it did when it was built. Recent multiple listing data from May 2026 put the citywide single-family median sale price in Beverly Hills near $5.62 million, with Trousdale trading 25 to 30 percent above that figure. The neighborhood commands a premium today and sits unambiguously inside the city that does not levy Measure ULA.
What This Means If You're Comparing Neighborhoods
Anyone comparing homes across the Westside right now is likely comparing across at least three tax regimes without realizing it, since neighboring cities like Santa Monica have enacted their own separate transfer measures with their own thresholds. The mailing address on a listing sheet tells you almost nothing about which regime applies. Only the parcel's actual jurisdiction does.
This does not make BHPO a lesser address. Homes there tend to sit on larger, more private lots than the Flats, with views that Beverly Hills proper often cannot match, and buyers who value that seclusion over transfer tax exposure have always found real value there. What it does mean is that the zip code cannot be the basis for comparing two properties, or for estimating what a sale will actually net after closing. The jurisdiction has to be confirmed on the parcel record, not assumed from the envelope.
For a seller sitting near either ULA threshold, or a buyer trying to model true carrying costs before making an offer, that confirmation should happen before a price gets set, not after an accepted offer goes into escrow. A property's legal description, available through the county assessor, settles the question definitively.
A Few Questions Worth Asking Before You Compare Two 90210 Listings
Does every 90210 address sit inside the city of Beverly Hills? No. The zip code covers both the incorporated city and the adjacent Beverly Hills Post Office area, which is legally part of Los Angeles.
How can I tell which jurisdiction a specific property is in? The county assessor's parcel record lists the governing city. A knowledgeable local advisor can confirm this in minutes, and it is worth doing before any serious pricing conversation.
Does this affect anything besides the transfer tax? Yes. Jurisdiction also determines which police and fire departments respond, which school district a child is zoned for, and which building department reviews permits and renovations.
This is not tax or legal advice, and thresholds and rates can change with future ballot measures. Anyone weighing a sale near either ULA threshold should confirm current figures with a qualified attorney or CPA before setting a price.
Understanding which side of an invisible line a property sits on is exactly the kind of detail that separates a casual search from an informed one. If you are comparing homes across Beverly Hills, Bel Air, or the surrounding Westside and want a clear picture of what a specific address actually costs to buy or sell, Kathy Marshall offers a private consultation built around precisely that kind of local detail.
