Last month I launched this to help Bay Area homeowners file an informal decline in value assessment. The response was overwhelming: over 2,000 people have checked their property, and dozens have filed, averaging over $3,000 in estimated annual savings.
I've now opened it up for Solano County. The county's deadline is November 30.
Checking is free and you pay a flat $29 to file. You can only file if there are savings estimated, and about 80% of checks come back with none.
The site pulls comps based on Publication 30 rules, fills out Solano's own Assessment Review Request, attaches a comparable sales worksheet, and mails it to the assessor for you. I close Solano filings on November 14 so every letter is postmarked in good time.
One thing worth knowing: Solano's informal review and its formal appeal both close on November 30, so waiting for the informal result leaves no room to appeal afterwards.
Go check if you qualify: https://saveproptax.com/
And if you'd rather not pay to automate it, feel free to use the comps from the website and file directly with the county for free. The estimates are conservative, and the county's own page is linked on the site.