How to Calculate and Give Notice of a Rent Increase in Rocklin

Three questions before any increase

Your tenant's renewal date is coming up, and your own costs have climbed: HOA dues, insurance, maybe a Mello-Roos special tax on the property tax bill. A rent increase seems fair. Before you pick a number, answer three questions in order.

First, is the home covered by the statewide cap at all? Second, if it is, what is the most you can charge over the next 12 months? Third, how much written notice does this increase need? Get any one of them wrong and the increase can be unenforceable, or worse, an overcharge you have to repay. No local layer applies: the Attorney General's chart of city and county rent stabilization laws lists no Placer County city, so the state rules are the ones to follow.

Where 7.7% and 8.6% come from

Civil Code 1947.12 caps increases over any 12-month period at 5% plus the percentage change in the cost of living, or 10%, whichever is lower. Which cost-of-living figure you use depends on where the home is. The statute uses the regional index where one exists, and the Attorney General explains that federal regional data is published only for the Los Angeles, Riverside, San Diego and San Francisco areas. Everywhere else, including Placer County, uses the California index published by the Department of Industrial Relations, measured April to April.

DIR's table shows the California index rose 2.7% from April 2024 to April 2025, and 3.6% from April 2025 to April 2026. Add 5% to each and you get the two figures on the Attorney General's chart for "All Other Counties": 7.7% for increases that start between August 1, 2025 and July 31, 2026, and 8.6% for increases that start between August 1, 2026 and July 31, 2027.

The date the increase takes effect decides which figure applies, not the date you write the notice. A notice served in early July for an increase starting August 15, 2026 uses 8.6%.

Working out the maximum for your tenant

The cap is not simply a percentage of today's rent. Work through it like this:

• Find the lowest gross rent charged for the home at any point in the 12 months before the increase takes effect. A move-in discount or credit that was listed separately in the lease does not lower that base.
• Multiply that lowest rent by the cap for the effective date. For an increase starting on or after August 1, 2026, multiply by 1.086. The result is the highest monthly rent allowed over the next 12 months.
• Add up every increase that takes effect within those 12 months. Together they cannot pass the result above.
• Count the increases. The same tenant's rent may go up in no more than two steps in a 12-month period.
• Round down, not up, if your math lands between cents, so you never sit a few cents over the line.

Giving notice the way Civil Code 827 requires

For a month-to-month tenancy, a rent increase must be in writing and delivered personally or by mail. The Attorney General's tenant page puts it bluntly: it is not enough to call, text or email that you plan to raise the rent. Mailing adds extra days under Code of Civil Procedure 1013, so build in time or deliver by hand.

The notice period depends on size. If the increase, together with all other increases in the 12 months before it takes effect, is 10% or less, give at least 30 days. If it is more than 10%, give at least 90 days. A lease or other agreement that requires longer notice controls. Because the Placer County cap is below 10%, a covered home will normally use the 30-day period; the 90-day period mostly matters for exempt homes.

During a fixed-term lease, rent usually changes only at renewal or as the lease itself allows. Two other limits apply to every home. Civil Code 1942.5 bars raising rent in retaliation within 180 days after a tenant's good-faith repair request or complaint. And the Attorney General notes that price-gouging protections tied to emergency proclamations may limit increases. SPMG's lease renewals page describes how renewals and rent changes are handled.

Exemptions, in short

Some homes are outside the cap. The main ones in Rocklin: a single-family home or condo whose owner is not a REIT, a corporation, or an LLC with a corporate member, but only when the exact statutory notice is in the lease (the relocating owner guide shows the required wording); housing issued a certificate of occupancy within the previous 15 years, which the newer vs 1990s home comparison explains; and a duplex where the owner lives in the other unit. A tenant paying with a Section 8 voucher does not make a market-rate home exempt. Exempt homes still need written notice under Civil Code 827.

If an increase goes over the line

Under Civil Code 1947.12(k), a tenant charged more than the cap allows can sue for the excess, the court may award attorney's fees, and willful violations can bring up to three times the overcharge. The Attorney General and local city attorney or county counsel can also enforce. If you find a mistake, correcting the rent and returning the excess promptly is usually the cleaner path.

Keep the cap rules on your calendar: the figure changes each August 1, and both the cap and just-cause sections are set to expire January 1, 2030 unless the Legislature acts. When the next figure is posted, the Attorney General's rent cap page is the place to check it.