offshore tax planning

To me the offshore tax planning must be executed, but several other shareholders of our company didn’t agree. When we put the company as a Off Shore Company is thinking about one day have the strength to find a professional company to help us offshore tax planning, now beat a retreat is not it does not pay. But few of them but also say what one says is plausible. The, say offshore tax planning is illegal. I really want to do not understand, everyone is cultural knowledge, so a thing didn’t know is how to return a responsibility? If the offshore tax planning is illegal, then I want to know, the economic society, what is not illegal.