In January 2012, Demi Moore needed an ambulance from her home above Sunset Boulevard. The 911 call went out, and for more than two minutes, dispatchers debated which department should respond. Her address said Beverly Hills. Her parcel did not sit inside the city of Beverly Hills at all.
That confusion was never really about an actress or an ambulance. It was about a boundary that has quietly shaped real estate above Sunset for a century, and it is more expensive to misunderstand today than it has ever been.
A Mailing Address Is Not a City
The section of hillside real estate known as the Beverly Hills Post Office, or BHPO, carries the same 90210 ZIP code as the city of Beverly Hills. It does not sit inside the city of Beverly Hills. The designation dates to the 1920s, when the federal government routed mail for a rural stretch of land, much of it part of the old Doheny Ranch, through the Beverly Hills post office. By the 1940s, buyers were choosing BHPO precisely because the address carried Beverly Hills prestige at a lower price than the city itself, even though property taxes there ran higher until Proposition 13 equalized rates statewide in 1978.
Today BHPO covers the hillside enclaves stretching from a few blocks above Sunset up to Mulholland Drive, roughly between Coldwater Canyon and Benedict Canyon. It includes some of the most guarded addresses in Los Angeles: Beverly Park, The Summit, Mulholland Estates, and stretches of Benedict Canyon and Franklin Canyon. Most sources place these parcels inside the city of Los Angeles proper, though a handful of accounts describe pockets of the canyon area as unincorporated county land, which only underscores the real point: jurisdiction has to be confirmed parcel by parcel, not assumed from the envelope.
Trousdale Estates sits in the same general hillside geography and carries the same 90210 address, but it was folded into the actual city of Beverly Hills when the city incorporated in 1914, an exception to the boundary drawn around the rest of the hills. Two neighborhoods that look identical from a listing photo can answer to entirely different city halls.
BHPO residents vote in Los Angeles elections, call the Los Angeles Police and Fire Departments, and send their children to schools zoned through the Los Angeles Unified School District rather than Beverly Hills Unified. None of that shows up on a mailing label. All of it shows up on a closing statement.
The Tax That Only Cares About the City Line
Since April 2023, the city of Los Angeles has collected an additional transfer tax on real estate sales above a set threshold, formally known as Measure ULA and known informally as the mansion tax. It applies only within the incorporated city of Los Angeles. It does not apply in Beverly Hills, Santa Monica, Culver City, or any other independent municipality in the county, because those cities operate under their own tax authority.
For transactions closing after June 30, 2026, the Los Angeles Office of Finance sets the active thresholds at $5,400,000 and $10,900,000. Sales between those two figures are taxed at 4 percent of the full sale price. Sales at $10,900,000 or above are taxed at 5.5 percent, also on the full sale price, not just the amount above the line.
That last detail matters more than it sounds. The tax is a cliff, not a bracket. A property that closes at $10,899,999 owes 4 percent, or roughly $436,000. A property that closes one dollar higher, at $10,900,000, owes 5.5 percent on the entire amount, or $599,500. A single dollar of negotiated price can move a seller's tax bill by more than $160,000, and that math only exists at all if the parcel sits inside the city of Los Angeles.
A comparable estate that closes the same week inside the actual city of Beverly Hills owes none of it. Only the standard countywide documentary transfer tax applies there, currently about 0.11 percent of the sale price, a fraction of what a BHPO neighbor pays on an equivalent number.
Here is what that looks like on a $10,900,000 sale, side by side:
| Cost component | BHPO parcel (City of LA) | City of Beverly Hills parcel |
|---|---|---|
| Measure ULA tax (5.5%) | $599,500 | Not applicable |
| City of LA transfer tax (0.45%) | $49,050 | Not applicable |
| LA County transfer tax (0.11%) | $11,990 | $11,990 |
| Approximate total transfer-related cost | $660,540 | $11,990 |
Same ZIP code. Same buyer pool. Same view of the basin. A difference of well over $600,000 in closing costs, determined entirely by which side of an invisible line the deed sits on.
Measure ULA is not a marginal detail for high-value hillside listings. As of January 2026, the city reported that the tax had generated more than $1 billion in cumulative revenue for affordable housing programs since it took effect. Research out of UCLA has estimated that the tax reduced the odds of a property selling above the $5 million threshold within the city by as much as 55 percent, a sign of exactly how much pricing behavior has shifted around this boundary.
Why This Matters More in BHPO Than Almost Anywhere Else
Most Los Angeles neighborhoods where ULA applies do not also compete, block by block, with an exempt neighbor that shares the same name recognition. BHPO does. A buyer comparing a $12 million estate in Beverly Park against a similarly priced property inside the actual city of Beverly Hills is not just comparing lot size and finishes. They are comparing a deal with a $660,000 tax exposure against one without it, on the seller's side, which inevitably works its way into how each property gets priced and negotiated.
For sellers, that means net proceeds cannot be estimated from the last comparable sale down the street unless that comparable sat in the same jurisdiction. For buyers making offers near a threshold, it means the seller's after-tax math may be pushing negotiations in ways that have nothing to do with the house itself.
Before listing or writing an offer on anything in the hills above Sunset, a few questions are worth answering with certainty rather than assumption:
- Pull the parcel record through the Los Angeles County Assessor to confirm which city actually holds jurisdiction, rather than relying on the mailing address.
- Confirm which police department, fire department, and school district serve that specific parcel, since BHPO boundaries do not follow a single clean line even within the same street.
- Model net proceeds using the gross sale price against the current thresholds, since ULA is calculated on the full price with no exemption for the amount below the line.
- Treat pricing near $5.4 million or $10.9 million as a strategic decision, not a rounding exercise, given how much a small price shift changes total tax exposure at those exact points.
- Confirm the tax's status before finalizing long-term plans, since a statewide ballot initiative could change how it applies in the near future.
The Political Backdrop Is Still Moving
Measure ULA has survived its early court challenges, but it remains contested. A statewide ballot initiative backed by the Howard Jarvis Taxpayers Association is targeting the November 2026 ballot with the goal of repealing or significantly limiting the tax. On January 27, 2026, the Los Angeles City Council declined to advance a broader rewrite of the measure, including a proposed 15-year exemption for new construction, to the June 2026 ballot. The council revisited the question on June 17, 2026, voting 9-5 to direct the city attorney to draft a possible November 2026 ballot measure exempting newly constructed multifamily and mixed-use housing from the tax for its first ten years, and separately advancing a hardship exemption for Pacific Palisades homeowners selling after the January 2025 wildfire.
None of that changes the math for a sale closing today. It does mean the boundary discussed here is worth revisiting closer to any future listing date, since the rules governing it have already moved twice on the thresholds alone since the tax began.
Frequently Asked Questions
Is every hillside home with a "Beverly Hills, CA 90210" address inside the city of Los Angeles? No. Trousdale Estates carries the same 90210 address and sits inside the actual city of Beverly Hills. Jurisdiction has to be confirmed by parcel, not by ZIP code or mailing city.
Who actually pays Measure ULA at closing? The seller. It is assessed at the time the deed records, calculated on the gross sale price, and layered on top of the standard city and county documentary transfer taxes that already apply to every sale.
Could this situation change before I sell? Possibly. A statewide repeal initiative is aiming for the November 2026 ballot, and the city council has already adjusted the thresholds once this year. Anyone planning a sale in the next twelve to eighteen months should treat the current rules as the ones to plan around, while checking for updates as the date approaches.
This kind of jurisdictional detail rarely shows up in a listing description, but it belongs in every pricing conversation for hillside property above Sunset. Jonas Heller works these enclaves regularly and can confirm exactly which city holds jurisdiction over a specific parcel before it goes to market. Request a private consultation to walk through the numbers on your address, not just its ZIP code.
