If the buyer/homeowner has not received the required Notice of his or her Three Day Right to Cancel, then the contract may be cancelled at any time until the required form of notice thereof is provided to them. Civil Code § 1689.6.
You can indeed cancel a real estate listing agreement in California. Sellers might be asking themselves, “under what circumstances?” And the answer to that is: almost any. Maybe you changed your mind and you decided you don't want to sell your house after all.
California case law suggests that where the listing agreement has a fixed term, it may not be unilaterally terminated by the agent (though the client may unilaterally terminate). The agent may "renounce" the agency, but if the client is damaged by the renunciation, the client may sue for damages.
Whether you change your mind about selling, have ethical or performance concerns about the agent, or you just don't find a buyer, you can get out of a listing agreement. But before you sign one, you should understand your options for terminating a listing agreement so you don't feel stuck in a bad situation.
If you're set on canceling, send a formal request in writing, either via email or certified letter. Be sure to include your property address, the date, and a clear statement that you're terminating the agreement. If you want to work with a different agent in the future, be clear about the termination timeframe.
A listing agreement is a binding contract, but there are a number of ways to get out of one. Whether you change your mind about selling, have ethical or performance concerns about the agent, or you just don't find a buyer, you can get out of a listing agreement.