Depends on the country you found the company.
But all and all, you don't "need" one. You can stay illegal, not pay taxes and be off with it.
License would come handy for the potential customers.
I think he can choose the hosting company that doesn't prohibit gambling so he can register the domain and the hosting at the same time and he can continue to build the website. but if he wants to buy the gambling site, then maybe he can move the hosting with the other hosting that doesn't have any prohibition about gambling site. but it is better to have a license to run gambling site because you will be safe to manage your gambling site and don't have to worry.