Force a free subscription to every user registration

Hi,
I've changed something on my website.
Before at the end of the registration form there were the 3 buttons to choose the subscription (BASIC Free, PREMIUM 1 and PREMIUM 2). So ppl choose one of them and in their profile were shown the right plan.

Now I've eliminated them from the registration form, they can pay a subscription in a second time, but when ppl registers on the website no sub is assigned to them (normally the BASIC free).

How can assing in automatic way the BASIC sub when an user register him self to the website and after when he wants can buy 1 of the other PREMIUM subs?

Thank you

How can assing in automatic way the BASIC sub when an user register him self to the website and after when he wants can buy 1 of the other PREMIUM subs?

Set it as the only plan displayed on your registration page and mark it as exclusive and default. If it needs to be non-exlusive ensure it's at least marked default so it's selected by default. If you don't want it displayed at all during registration you can use CB Auto Actions acting on the after user registration trigger to give them a subscription to it using the CB Paid Subscriptions action.