San Mateo County, CA Rental Property Rules: Rent Increase Notice (2026)
Key Facts
- Notice method
- Certified letter to tenants
- Filing deadline
- 60 days before increase
- Applies to
- Mobilehome park spaces only
- Geographic scope
- Unincorporated county only
- Standard cap
- 75% of CPI or 5%
Summary
In unincorporated San Mateo County, a mobilehome park owner seeking a space-rent increase above the standard CPI cap must file a petition with the County Hearing Officer 60 days beforehand and send affected tenants a certified notice letter stating the requested amount.
The petition shall be filed with the Hearing Officer no later than sixty (60) days before the desired date the requested rent increase is to take effect.3.The petition shall contain a copy of a certified letter sent to the affected tenants notifying them of the petition and the amount of increase requested.4.The petition shall contain a statement attesting to the availability of any records required by the Hearing Officer to complete his or her review of the request for rent adjustment. Records shall include, but not be limited to, any audits of the mobilehome park's books, financial statements, and records relating to any governmental or utility assessments which have been levied upon the mobilehome park.5.The petition shall be accompanied by a check or money order in the amount of two thousand dollars ($2,000.00) to cover costs incurred by the County in fulfilling the Hearing Officer's responsibilities. The fee is nonrefundable. However, at the conclusion of the hearing, and upon making a finding that the petitioner has both successfully pursued the petition and pursued it in good faith, the Hearing Officer may grant to the petitioner a monthly surcharge to be added to the rents of the tenants to recover this fee paid to the County. Such a surcharge shall be a limited-duration pass-through to be paid monthly by the tenants over a period of five years.6.The petition shall be submitted under penalty of perjury. (Ord. 4188, 9/23/03)
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 47).
Full Breakdown
Chapter 1.30's rent adjustment process (Ord. Code § 1.30.040(B)) governs only mobilehome park spaces in the unincorporated county, and only increases above the annual cap set by § 1.30.030 (75% of the CPI change or 5%, whichever is less). To seek a larger increase, the park owner must file a petition with the Hearing Officer no later than 60 days before the desired effective date, accompanied by a certified letter sent to the affected tenants notifying them of the petition and the exact amount of increase requested. Standard CPI-capped increases carry no separate notice mandate in this chapter.
Violations & Fines
Under § 1.30.090, a tenant may refuse to pay any rent increase issued in violation of this chapter; that refusal is a valid legal defense against any action brought to recover possession of the mobilehome space or to collect the increase.
Frequently Asked Questions
Does this notice rule cover apartment rent increases?
What if a park owner raises rent above the cap without notice?
Sources & Official References
Other rules in San Mateo County
California rules heatmap·Compare San Mateo County to another location·View the California rental property rules overview
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