This initial version of this page originated in the Second Life Knowledge Base created by Linden Research, Inc.
What happens to land I own on the mainland if I downgrade from a Premium account to Basic?
Basic
accounts can't own land on the mainland. If you're going to downgrade
from your Premium account to Basic, you should relinquish your land
holdings on the mainland by abandoning or selling your land. You'll be
billed for your land holdings for the last billing cycle.
If you downgrade while the land is still yours, you'll continue to
be charged for it. Since it's highly unusual for Basic accounts to own
land on the mainland, your account may be automatically held for review
and your land may be reclaimed from you.