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HomeCommercial CodeDiv. 3Ch. 4§ 3403 Unauthorized Signature Effectiveness

§ 3403 Unauthorized Signature Effectiveness

Commercial Code·California
AI Summary·Official Text·Key Terms·Related Statutes·References
AI SummaryVerified

§ 3403 Unauthorized Signature Effectiveness

This rule says a signature that someone isn’t allowed to make doesn’t count, unless the person who pays for it does so in good faith, and the signature can be approved later.

Key Takeaways

  • •A signature made by someone who isn’t allowed to sign is usually not valid.
  • •It becomes valid only for the person who pays for it in good faith.
  • •The signature can be approved later (ratified).
  • •If a group needs several signatures, missing even one makes the whole signature invalid.
  • •The person who made the unauthorized signature can still be held responsible.

Example

A small business needs two owners to sign a check, but only one owner signs it.

Because one required signature is missing, the check’s signature is not valid. If the bank still pays the check, the payment only works for the person who gave the money, and the owner who signed without permission can still get in trouble.

AI-generated — May contain errors. Not legal advice. Always verify source.

Official Source
View on CA.gov

§ 3403 Unauthorized Signature Effectiveness

(a) Unless otherwise provided in this division or Division 4 (commencing with Section 4101), an unauthorized signature is ineffective except as the signature of the unauthorized signer in favor of a person who in good faith pays the instrument or takes it for value. An unauthorized signature may be ratified for all purposes of this division. (b) If the signature of more than one person is required to constitute the authorized signature of an organization, the signature of the organization is unauthorized if one of the required signatures is lacking. (c) The civil or criminal liability of a person who makes an unauthorized signature is not affected by any provision of this division which makes the unauthorized signature effective for the purposes of this division. (Repealed and added by Stats. 1992, Ch. 914, Sec. 6. Effective January 1, 1993.)

Last verified: January 10, 2026

Key Terms

unauthorized signaturegood faithratifiedauthorized signatureliability

Related Statutes

  • § 3418 Recovery For Mistaken Payment
  • § 3404 Impostor-Induced Instrument Endorsement
  • § 3406 Negligence In Instrument Forgery
  • § 3417 Draft Transferor Warranties
  • § 3419 Accommodation Party Liability

References

  • Official text at leginfo.legislature.ca.gov
  • California Legislature. Commercial Code. Section 3403.
View Official Source