A five-bedroom spec mansion just hit the market at 1465 Donhill Drive, priced at $35 million for roughly 15,000 square feet of house. The developer, Ramtin Ray Nosrati of Huntington Estate Properties, built it with a rooftop pickleball court, a hidden theater behind a suede-walled door, and a motor court that fits ten cars. The listing carries a 90210 address, the same zip code stamped on Rodeo Drive storefronts and Trousdale Estates driveways.
Here's what that address doesn't tell you: if the home sells anywhere near its ask, the seller owes Los Angeles roughly $1.9 million in transfer tax. A comparable estate a few blocks south, inside the actual city limits of Beverly Hills, would owe none of it.
Same zip code. Same prestige mailing address. A tax gap that runs into seven figures. That gap is the story worth understanding if you're shopping, selling, or just trying to make sense of what a Beverly Hills address really means.
The zip code that doesn't match the city line
When Beverly Hills incorporated in 1914, its northern border stopped roughly a mile short of Sunset Boulevard, with the notable exception of what later became Trousdale Estates. Everything north of that line, climbing into the hills toward Mulholland Drive, stayed part of the City of Los Angeles. For decades that hillside land sat mostly undeveloped, part of the old Doheny Ranch.
In 1963, the U.S. Postal Service assigned the 90210 zip code to both the incorporated city of Beverly Hills and the LA-jurisdiction hillside neighborhood it serves by mail, because the Beverly Hills post office branch was the one handling deliveries up there. The result is a neighborhood everyone calls the Beverly Hills Post Office, or BHPO, that has never been part of the city of Beverly Hills at all. It stretches from about a mile north of Sunset up to Mulholland Drive and holds some of the most recognizable gated addresses in the region: Beverly Park, The Summit, Mulholland Estates, and Beverly Ridge Estates.
Donhill Drive sits inside that stretch. So the $35 million listing carries a Beverly Hills mailing address while legally answering to Los Angeles City Hall.
A boundary sharp enough to confuse 911
The line between the two jurisdictions is not a matter of interpretation. It determines which police department responds, which fire department shows up, and which school district a child is zoned into. BHPO residents rely on the Los Angeles Police Department and Los Angeles County Fire rather than Beverly Hills Police and Fire, and public school assignment runs through the Los Angeles Unified School District rather than Beverly Hills Unified.
Yet the boundary is invisible enough on the ground that even emergency dispatchers have struggled with it. In January 2012, when actress Demi Moore needed an ambulance at her BHPO home, Beverly Hills and Los Angeles 911 operators reportedly spent more than two minutes sorting out which department should respond, according to CBS Los Angeles reporting on the incident. A hard legal line, and a soft practical one, sitting on top of each other.
That contradiction matters more today than it did in 2012, because the financial stakes on either side of that line have grown considerably.
The tax line, in dollars
Los Angeles' Measure ULA, the city's additional real property transfer tax, applies only within the incorporated City of Los Angeles. Because Beverly Hills is its own self-governing municipality, properties in the Flats, Trousdale Estates, and the Gateway area sit outside ULA's reach entirely. BHPO properties, despite the address, sit squarely inside it.
As of July 1, 2026, the Los Angeles Office of Finance's current thresholds assess a 4 percent tax on sales between $5.4 million and just under $10.9 million, and 5.5 percent on anything at or above $10.9 million. The tax is calculated on the full sale price, not just the portion above the threshold, which is what makes crossing a bracket line so expensive. A property selling for exactly $5.4 million owes $216,000. A property selling for exactly $10.9 million owes $599,500.
At the Donhill Drive asking price, that top bracket works out to roughly $1.9 million, a bill that a neighboring estate technically inside Beverly Hills would never see. And Donhill Drive is not an isolated case. Just steps from the new listing, Nosrati sold a neighboring project, a roughly 13,000-square-foot home called Serenity, to Fashion Nova founder and CEO Richard Saghian for $32 million last year. Both homes sit on the same cul-de-sac, both carry the same 90210 mailing address, and both fall on the Los Angeles side of a line that most buyers never think to check.
Why sellers price to the dollar near the threshold
Because the tax applies to the entire sale price the moment a deal crosses a bracket, sellers on the Los Angeles side of the 90210 line have real incentive to price just under a threshold rather than just over it. A home listed at $5.4 million clears the 4 percent bracket cleanly. A home listed one dollar higher does not get taxed on that one dollar. It gets taxed on the whole $5.4 million.
That single design choice, a gross-receipts style tax rather than a marginal one, is why so much BHPO listing strategy revolves around staying just under a line rather than negotiating a slightly higher number. It is also why sellers in Beverly Hills proper never have to think about it at all. The tax simply does not exist on their side of the boundary.
What this means if you're comparing homes in 90210
If you're evaluating properties across the 90210 zip code, the mailing address tells you almost nothing about which government actually holds jurisdiction over the parcel, which services respond, or what a seller will net at closing. Two houses across the street from each other can carry identical addresses and completely different tax exposure.
The practical fix is straightforward. Before writing an offer or setting a list price near the ULA thresholds, confirm which municipality actually governs the parcel, not the zip code on the envelope. The Los Angeles County Assessor's parcel records will show it clearly, and it is worth confirming with the relevant planning department directly rather than assuming based on the address, the neighbors, or even the listing photos.
None of this makes BHPO a lesser choice. The neighborhood offers larger lots, hillside privacy, and gated communities that the flatter, more walkable parts of Beverly Hills proper simply don't have room for. It just means the decision involves a line most people never think to look for, one that happens to run straight through one of the most recognizable zip codes in the country.
A few questions worth asking before you write an offer
Does every home with a 90210 zip code sit inside the city of Beverly Hills? No. The zip code covers both the incorporated city of Beverly Hills and the BHPO area, which is legally part of the City of Los Angeles despite the shared mailing address.
Is Measure ULA the only cost that differs across the line? It's the most immediate one for sellers, but it's not the only difference. Police, fire, and school district assignment all shift depending on which side of the boundary a parcel sits on.
Where exactly does the line run? Roughly a mile north of Sunset Boulevard, following the original 1914 incorporation boundary, with the notable exception of Trousdale Estates, which sits inside city limits despite its position in the hills. From there the LA-jurisdiction BHPO area stretches north to Mulholland Drive.
Does the tax gap mean Beverly Hills proper is automatically the better buy? Not automatically. It means the tax exposure should be part of the comparison, alongside lot size, privacy, and the kind of home you're actually trying to buy.
A 90210 address has always carried weight. What it doesn't carry, on its own, is any guarantee about which government, which services, or which tax bill comes with it. If you're weighing a home anywhere in that zip code, from a flats bungalow to a Donhill Drive spec mansion, that's the kind of detail worth checking before the number on the listing becomes the number at closing.
If you're comparing homes across the 90210 line, or anywhere else on the Westside, Team Stacy White can walk the boundary with you before you write an offer. Let's Find Your Westside Home.
