I have no experience with it and don't live in CA, but I found this using AI:
maybe it's helpful, not sure
The City of Los Angeles requires a business tax registration certificate (BTRC) for anyone who conducts business within the city
. The tax is based on a company's worldwide gross receipts attributable to its business activities in Los Angeles.
Business tax registration certificate
Who must register: Any individual or company conducting business, including home-based and online businesses, must register with the Office of Finance. Independent contractors and gig workers are also typically required to register and report their income.
How to register: You can register for a new BTRC online via the city's Tax and Permit System. You may also need a federal Employer Identification Number (EIN) before you can register with the city.
Taxable gross receipts
The tax is calculated based on your taxable and non-taxable gross receipts.
A Small Business Exemption applies to registered businesses with worldwide gross receipts of $100,000 or less.
The tax measure, filing status, and tax liability are determined by the business's industry, such as wholesale sales or professional and personal services.
Payments and filing
Annual renewal: Business tax renewals are due by the last day of February each year.
Online payments: The Office of Finance allows you to make online payments for your tax renewals and any outstanding balances.
Forms and account updates: You can find necessary tax forms on the Office of Finance website. If your business moves, you must submit a Taxpayer Information Update Form to notify the city of the new address.
For more information
Los Angeles Office of Finance: The official city resource for business tax information.
Website: finance.lacity.gov
Phone: Call (844) 663-4411