All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Commercial insurance is among the forbidden contracts because it includes risk, Riba (interest and/or usury) and gambling as we clarified in Fatwa 81425.
Working as a surveyor who calculates the loss for insurance companies is helping in forbidden insurance; rather, the insurance estimate depends on the report of the surveyor and this is helping in this work.
Therefore, working in this field is forbidden and the money the surveyor is paid for this work is forbidden, whether or not he is employed by the company.
However, if you help the people who had already taken insurance coverage and guide them in order to get their right from the insurance company, and their right is just the installments which they had paid to the insurance company, then it is permissible for you to take a specified fee with the consent of both parties.
Allaah Knows best.