One name, everywhere: the business name, the DBA and the CSLB record
In one paragraph
Your business has exactly one legal name for contracting purposes: the one on the CSLB record. The bond, the workers' compensation certificate, the contracts, the permits, the truck and the ads all carry that name, spelled that way. A DBA is allowed only if CSLB has it on file, it fits your entity type and classification, and the county has the fictitious business name statement. Changing the name later is a 90-day reportable event, and a change that creates a new entity means a new license number.
The rule
B&P 7059.1 forbids any business name that indicates classifications you do not hold or that is incompatible with your entity type, and allows only one business name per license. B&P 7117 makes acting as a contractor under any name other than the one on the license a cause for discipline. Any change to the business name, address or personnel must be reported to CSLB within 90 days under B&P 7083, and a fictitious business name statement must be filed with the county within 40 days of using the name (B&P 17910).
Why it matters
A bond written to the wrong name is rejected and the 90-day issuance clock keeps running. A contract signed under a name CSLB does not have on file gives the customer a license-law defense and gives CSLB a discipline count. The cleanest way through Phase 0 is to pick the name once, register it once, and never let a second version of it appear anywhere.