Unofficial clan tags don't expire.
The clan system has been re-implemented. This unfortunately deleted the existing clans, both official and unofficial. Official clans don't need to re-apply. But they do need to contact a moderator for the clan (such as co-leader or leader) to rebuild the clan and reinvite everyone from scratch. I assume this is because official clans have their own board.
Unofficial clans have to reregister their names, which is why it's costing you 10k.
Toriclan tags don't expire lol.