The costs and rules around buying or selling a house here
The surprises come from taxes: a second property tax bill after you buy, transfer tax when you sell, and California rules that let older owners keep a low tax base when they move.
Last checked Oct 20, 2026
Just bought? Expect a second tax bill
Months after closing, the county reassesses the house at your purchase price and sends a separate bill for the difference, prorated for the rest of the year. Escrow doesn't pay it and your lender's impound account usually doesn't either. Example: buying a house whose old taxable value was $500,000 for $2.5 million adds about $24,000 a year in tax. The county's estimator shows your amount.
You can appeal within 60 days of the notice. Also file the homeowners' exemption right away; it isn't automatic.
Selling: what you'll pay
| Cost | Amount | Example on $3M |
|---|---|---|
| County transfer tax | $1.10 per $1,000 | $3,300 |
| City transfer tax: Mountain View only | $3.30 per $1,000 up to $6M (Measure G, 2024) | $9,900 |
| City transfer tax: Cupertino, Sunnyvale | None found | $0 |
Federal capital gains: up to $250,000 of gain ($500,000 for a married couple) is tax-free if the house was your main home for 2 of the last 5 years. Long-time owners here often have gains far above that, so talk to a tax preparer before listing.
Moving at 55+: keep your low tax base (Prop 19)
Owners 55 and older, severely disabled owners and wildfire or disaster victims can move their current taxable value to a new home anywhere in California, up to three times. If the new home costs more, only the difference is added.
Example
~$19,700 a yearA long-time owner sells for $2.5 million a house whose taxable value is only $800,000, then buys another $2.5 million home. Without Prop 19 they'd pay tax on $2.5M. With it they keep paying on $800,000: about $1.7M × 1.16% less each year. If the new home costs more than the old one sold for, the extra is added to the taxable value.
How: buy the new home within 2 years of selling the old one, then file the claim with the Santa Clara County Assessor within 3 years of buying.
Leaving the house to your children
Since 2021, a child keeps the parent's low tax base only if they move in as their main home within one year, and only for about $1 million of value above the parent's taxable value. A child who rents it out or keeps it empty is reassessed at market value. This catches many families by surprise.
Things to fix or disclose before listing
- Water fixtures: sellers must disclose toilets over 1.6 gallons per flush, showerheads over 2.5 gallons per minute and faucets over 2.2. Swapping them is cheap and avoids friction in escrow.
- Unpermitted work: must be disclosed. Retroactive permits are possible but can mean opening walls.
- Sewer lateral: none of the three cities requires an inspection when you sell (Mountain View requires one for major remodels and ADUs).
- Homestead protection is automatic. California protects your home equity from most creditors (about $722,000 here). You don't need to pay a service to "file a homestead."
Facts are checked against the public sources listed on each page. Rates change every year; each page shows when it was last checked. Individual bills are confidential in California, so personal numbers are estimates from public rates. Nothing here is legal, tax or insurance advice.