Assumed-Name (DBA) Registration Requirements in California

At a glance

Requirements one by one

Who must register

The duty falls on anyone who "regularly transacts business in this state for profit under a fictitious business name" (§ 17910). Whether a name is "fictitious" depends on who you are (§ 17900):

• A sole proprietor needs a filing whenever the business name leaves out their surname or hints at other owners. "Maria Chen" doing business as "Chen Accounting" needs one (no first name is not the issue — the statute keys on the surname and on words like "Company," "& Associates," or "Brothers" that "suggest the existence of additional owners"). "Maria Chen, Bookkeeper" does not.
• A general partnership needs one unless the name includes the surname of every general partner.
• An LLC or corporation needs one for "any name other than" the exact name on file with the California Secretary of State. An LLC operating under its full registered name files nothing (see What trips people up).

Only for-profit business triggers the chapter.

Where and when to file

You file the fictitious business name statement with "the clerk of the county in which the registrant has his or her principal place of business" (§ 17915). If your business has no California location, you file with the Clerk of Sacramento County. The deadline is "not later than 40 days from the time the registrant commences to transact" business under the name (§ 17910(a)) — counted from when you start using the name, not from when you form the entity.

A January 2027 form change

Chapter 237, § 39, of the 2026 Statutes was enacted on September 14 without immediate effect. Under article IV, § 8(c)(1) of the California Constitution, its § 17913 amendment takes effect January 1, 2027. Beginning then, the registrant's signature must include “the signer's printed name and the title that gives them authority to file pursuant to Section 17914.” The chapter also applies the existing knowingly-false-statement misdemeanor and $1,000 maximum fine to the information on that revised statement. The filing office, filing and publication deadlines, five-year term, and county-set fee structure do not change.

The newspaper-publication step

After filing, you must publish the statement. Section 17917 gives you 45 days from filing to run it "in a newspaper of general circulation in the county where the fictitious business name statement was filed," and the publication itself follows Government Code § 6064: "once a week for four successive weeks." Within 45 days after the last insertion, you file the newspaper's affidavit of publication with the same county clerk. If there is no qualifying newspaper in your county, you publish in an adjoining county; if you have no California business location, you publish in Sacramento County.

How long it lasts

A statement "expires five years from the date it was filed" (§ 17920(a)). To keep using the name, you refile before it lapses. Two events end it sooner: a change in the facts on the statement (it expires 40 days after the change, with a narrow partnership-withdrawal exception under § 17923), and filing a statement of abandonment.

What happens if you skip it

California does not fine you for merely operating unregistered; instead it shuts the courthouse. Until the statement "has been executed, filed, and published," you "may [not] maintain any action upon or on account of any contract made" in the fictitious name (§ 17918). Separately, knowingly filing or publishing a false statement "shall be guilty of a misdemeanor" punishable "by a fine not to exceed one thousand dollars ($1,000)" (§ 17930).

What trips people up

• An entity using its exact legal name files nothing. The chapter only reaches a name "other than" the one registered with the Secretary of State (§ 17900). "Blue Oak Design LLC" operating as "Blue Oak Design LLC" has no DBA; the same LLC operating as "Blue Oak Studio" does.
• The suit-bar is a delay, not a death sentence. If you sued and then discovered you never filed, § 17918 blocks the case — but it is curable. You file and publish, and you can proceed; the underlying contract stays valid. The lesson is to file before you need to enforce anything, because a defendant will raise the bar at the worst moment.
• A change in the facts quietly expires your statement. A new business address or a change in ownership expires the statement 40 days after the change (§ 17920(b)) — long before the five-year mark — so update it when anything on it changes.
• Registering does not lock up the name. The filing is "not intended to confer any right or advantage" and only makes owners' identities public (§ 17900(a)). Another business can file the same name in another county, and a prior trademark holder can still stop you. Brand protection is a trademark question.

Common questions

Do I need a DBA to open a business bank account? The law does not say so, but banks routinely require the filed statement (and often the published copy) before opening an account in the business name. Filing early avoids that holdup.

I run my business from home in one county but sell across California — where do I file? With the clerk of the county of your principal place of business (§ 17915). You may also file in other counties, but the home-county filing is the required one.

Does filing stop a competitor from using my name? No. Registration is public notice only (§ 17900(a)). To keep others from using a brand name, look at state or federal trademark registration, which is a separate process.

How much does it cost? The chapter sets no state fee. The county clerk charges its own filing fee, which varies by county, and you separately pay the newspaper that runs your four-week publication. Budget for both.

Statutes and sources

• Cal. Bus. & Prof. Code § 17900 — defines "fictitious business name" by entity type and states the public-notice purpose. Official text (accessed 2026-07-23).
• Cal. Bus. & Prof. Code § 17910 — duty to file within 40 days of commencing business. Official text (accessed 2026-07-23).
• Cal. Bus. & Prof. Code § 17915 — filing with the county clerk of the principal place of business, or Sacramento County. Official text (accessed 2026-07-23).
• Cal. Bus. & Prof. Code § 17917 — 45-day publication window and affidavit. Official text (accessed 2026-07-23).
• Cal. Gov. Code § 6064 — "once a week for four successive weeks." Official text (accessed 2026-07-23).
• Cal. Bus. & Prof. Code § 17918 — suit-bar until filed and published. Official text (accessed 2026-07-23).
• Cal. Bus. & Prof. Code § 17920 — five-year term and early-expiration triggers. Official text (accessed 2026-07-23).
• Cal. Bus. & Prof. Code § 17930 — misdemeanor for a knowingly false statement. Official text (accessed 2026-07-23).
• 2026 Cal. Stat. ch. 237, § 39 (SB 1445) — amends § 17913 to add the signer's printed name and authority-conferring title to the statement. Official chaptered text (accessed 2026-09-19).
• Cal. Const. art. IV, § 8(c)(1) — supplies the January 1 general effective date for a regular-session statute enacted at least 90 days earlier. Official constitution PDF (accessed 2026-09-19).