In 2017 I registered LLC in California. It is a software development agency. I have no physical office and no employees in LA. My home address is my LLC mailing/legal address, which is in Los Angeles. Recently I received a letter from City Of Los Angeles says that I should apply for "City of Los Angeles Business Tax Registration Certificate". It is not clear if software development agency as sole proprietary LLC should obtain LA Business Tax Registration Certificate.
Question: Can anyone explain why is it needed, what does it impose, will I pay extra tax to LA, if yes - how much?. Should I register at all if in 1 month I will be closing my LLC in California?
I couldn't find any software development category when tried to apply for LA Business Tax Registration Certificate online. I tried to read through finance.lacity.org FAQ - but is not informative.