Rent increase notice period rules in Contra Costa are not one-size-fits-all. A landlord who assumes every increase gets a 30-day notice can walk into a 90-day requirement without realizing it, and that mistake voids the increase for months.
The Real Challenge: Two Different Clocks, Same Property
The challenge is that the required notice period is not set by a single rule. State law and local ordinances each have their own trigger, and they run side by side. A property in Concord can be subject to both AB 1482 and the city’s own rent ordinance, and the longer notice wins. In Walnut Creek, the city has no rent ordinance, but AB 1482 still applies to most properties. The result is that the same rent increase can require a 30-day notice on one property and a 90-day notice on the one next door, based on factors the owner may not have checked recently.
What most owners get wrong is treating the notice period as a fixed number. It moves. The split between 30 days and 90 days depends on how the increase is calculated, whether the property is covered by a local ordinance, and whether the tenant has been there long enough to trigger a longer notice under state law. None of these are static, and a calendar built once in January will be wrong by summer.
A Genuine Partial Answer: The Calendar That Prevents the Mistake
Here is the framework we use to build a rent increase calendar that catches the 30-day/90-day split before it becomes a problem. It is not legal advice, and it is not a substitute for checking the current ordinance text for your city. But it is the operating logic that keeps the process straight.
- Start with state law. Under AB 1482, a rent increase that exceeds a certain threshold—calculated annually and tied to inflation—requires a 90-day notice. Increases at or below that threshold require 30 days. The threshold itself changes each year, so you cannot use last year’s number.
- Layer on the local ordinance. Concord’s rent ordinance has its own rules. It carves out single-family homes, condos, and accessory dwelling units, but for covered properties it can impose a different notice requirement or a different cap. If the local rule is stricter, it controls.
- Check the tenancy length. Even when the increase amount would normally allow a 30-day notice, a tenant who has lived in the unit for more than a year may be entitled to 60 days under state law, and some local rules extend that further.
- Build the calendar backward. Pick the date you want the increase to take effect. Count backward the required number of days, then add a buffer for delivery method—personal service, posting, or mail each have their own effective dates. The date you hand over the notice is not the date it is legally received.
This framework works because it forces you to answer the three questions that determine the notice period—state cap, local coverage, tenancy length—before you pick a date. When we run this for a Concord property, we often find that the notice period is longer than the owner assumed, not because the rules changed but because they were looking at the wrong rule.
What Is Left: The Specifics That Change by City and by Year
What the framework cannot give you is the exact number of days for your property right now. That depends on the current AB 1482 threshold, the current Concord ordinance text if the property is in Concord, and the tenant’s move-in date. It also depends on whether the property is exempt from either rule—Concord’s exemption process requires a specific notice form, and missing it can bring the property under the ordinance even if it would otherwise be exempt. We covered that form and its deadline in Concord Exemption Notice: Form, Deadline and Penalty.
Walnut Creek landlords face a different version of this. Without a local rent ordinance, the notice period is driven almost entirely by AB 1482 and the tenancy length. But Walnut Creek has its own rules around things like the TBID assessment, which can affect the total cost picture even if it does not change the notice period. We wrote about confirming that status in Confirm Your Walnut Creek TBID Assessment Status.
How We Walk You Through It
When we work through this with an owner, we do not start with the notice. We start with the property file. We confirm which ordinances apply, whether any exemptions are in place and documented, and what the current state threshold is. Then we map the tenant roster against those rules—each unit gets its own calendar entry, because the notice period can differ from one door to the next.
From there, we build the notice itself. The content of the notice matters as much as the timing. A notice that states the wrong effective date or the wrong legal basis can be challenged even if the calendar was correct. We make sure the notice references the specific ordinance section that applies, and we track delivery so there is a record of when the clock started.
This is the kind of process that lives inside our property management workflow. It is not a one-time fix. It is a recurring calendar that updates as thresholds change and tenancies age. The system flags the next increase date well before the notice deadline, so the decision about the amount and the timing happens with room to spare.
Why the Calendar Matters More Than the Notice
Most of the mistakes we see are not about the notice itself. They are about the calendar that was supposed to produce it. An owner who knows the rules but does not have a system to apply them on time ends up serving a 30-day notice when 90 was required, and by the time the error is caught, the increase is delayed by months. In a market where carrying costs are real, that delay is a direct hit to the property’s performance.
The fix is not more knowledge. It is a process that turns the knowledge into a date on a calendar, with enough lead time to adjust if something changes. That is what we build, and it is what keeps a rent increase from turning into a compliance problem.
If you are managing this yourself, start by confirming which ordinance applies to each property and what the current state threshold is. Then build your calendar backward from the desired effective date, using the longer of the state and local notice periods. If you want a second set of eyes on it, we are set up to do exactly that. Contact us here and we will walk through your specific situation.
What is the one rent increase deadline you have circled on your calendar right now, and how confident are you that the notice period is correct?
About this article. This is general information and our own opinion, written from how we run operations for owners and businesses in Contra Costa County. It is not legal, tax, accounting, financial or other professional advice, it is not a recommendation to take or avoid any action, and it is not a substitute for advice about your own property, tenancy or business. CAO Investment Group is not a law firm, and reading this does not create an attorney-client or any other professional relationship. Local ordinances, fee schedules, forms, thresholds and deadlines change often and differ from city to city within Contra Costa County — anything here may be out of date by the time you read it, including as of the publication date shown above. Verify anything you plan to rely on against the current rules published by your own city or county, and speak to a qualified attorney, CPA or licensed professional about your specific situation before you act. We make no warranty that this information is current, complete or accurate, and we accept no liability for any action taken or not taken on the basis of it.
