In California, proving your own performance is a mandatory requirement to succeed in a breach of contract lawsuit. As a plaintiff, you carry the burden of proof for the second essential element of the claim: that you either fulfilled your obligations or had a legally recognized reason for not doing so.

To satisfy this requirement, you must demonstrate one of the following:

• Full Performance: You must show that you fulfilled all contractual duties exactly as specified in the agreement.
• Substantial Performance: This applies if you completed all major aspects of the contract, even if minor, technical details were left unaddressed.
• Legal Excuse: You may be excused from performance if the other party’s actions prevented you from performing, if performance was waived, or if a supervening event made the contract’s purpose impossible to achieve.

Documentation is critical for this element. Plaintiffs typically use written agreements, emails, and performance records to build an unassailable foundation for their claim. Under CACI 303 jury instructions, if a defendant’s breach is found to be “material,” the plaintiff may be discharged from further obligations, but the initial burden to show performance (or a valid excuse) remains a prerequisite for filing the suit.

• Elements of Breach of Contract California: Essential Legal Guide