Define the job
A written estimate should identify the vehicle and the proposed service with the labor, parts and relevant charges required by applicable rules. The customer should understand the diagnostic or repair scope before authorizing compensated work.
Document approval
California BAR rules require proper authorization and records. If diagnosis uncovers other work, the repair dealer generally needs supplemental authorization before that additional repair or charge proceeds.
Keep the outcome clear
A final itemized invoice and appropriate transaction records give the customer and dealer a traceable repair history. Exact obligations and exceptions should be checked against current BAR guidance.