Industrial and commercial registration is not a necessary condition for you to obtain the company's shareholder status. Industrial and commercial change registration only plays a publicity role, such as subsequent equity transfer. The third party who receives your equity can find out from the industrial and commercial registration information that you are a shareholder of the company, and can identify you as a bona fide third party and have the right to dispose of the registered equity. If the equity you hold is actually held on behalf of others, the legitimate rights and interests of bona fide third parties are protected by law.
Without industrial and commercial registration, it has no publicity effect on the outside world, that is, when communicating with the outside world or when the company's creditors claim debts, it has no influence on you, because you are not the nominal shareholder of the company, but other shareholders of the company can claim compensation from you according to the signed occupation agreement after assuming the responsibility of repaying debts.
But within the company, if all shareholders sign for you to join the company, then you are the shareholder of the company, and you can enjoy the corresponding shareholder rights according to the agreement, including making industrial and commercial changes, voting rights and dividend rights for you.
To sum up, you are actually a shareholder of the company, but there are differences and differences in internal and external effects.