It sound very simple, but I can´t see the solution:

I have three plans:

Plan A = lifetime membership for customers (without costs)
Plan B = lifetime membership for trader (without costs)
Plan C = monthly fee for trader (with costs)

How can I manage it, that the plan-C-user fall back on plan B, when there plan expire?

I think, it´s basic, maybe I worked today to much and don´t see the solution. But a short explanation would be great!

Thanx!
Mike

Thanx for your fast reply, Krileon!

Your first idea has the consequence, user has to do two steps to achieve the desired membership. I think, it´s not the best way.
Your second idea was in the beginning my choice, but the point is, you can´t choose Plan B seperatly. If plan C is a child of Plan B, and I choose Plan B, Plan C get also activated. Can you confirm this?
So, if we can´t avoide this (can´t we?), my idea is now to build a fourth plan, which is just a double of Plan B:

Plan A = lifetime membership for customers (without costs)
Plan B = lifetime membership for trader (without costs)
-> Plan C = lifetime membership for trader (without costs)
-> Plan D = monthly fee for trader (with costs)

If someone like to choose Plan B, Plan C will automaticly activate, which has the same terms. Little bit confusing for the members, but I think, it´s a matter of design and text.

Thanx for your reply.
I found the solution.

I wrote: "If plan C is a child of Plan B, and I choose Plan B, Plan C get also activated."

That was my main problem and I looked for a workaround.

But the point was: Plan C was declinated as "Standard" plan. That was the reason for my problem above. I change the status of the plan and now I can choose Plan B without automatic activating Plan C.