do all brokers need to be on insurance

Most brokers will ask to be listed as a certificate holder. So you'll call your insurance company and tell them you're setting up with a new broker and need they want to be listed. Your insurance will ask for name of the broker, their address, and email to send it to them. Make sure they send it to them and you because it's not uncommon for an insurance person on the phone to misspell an email address or something. Some insurers have an online portal so you can do it yourself.

Under no circumstances allow them to be "Additionally Insured", this option costs extra money and has a lot of potential for fallout if something goes wrong. Maybe someone else here can give a caveat to this but for general freight I would skip any broker/load that made the "Additionally insured" request.

 

Certificate holder is most you can offfer them. If they want more move on.