An outstanding payment blocks new bookings.
The system retries the outstanding payment automatically the next day. If the charge goes through, your account is reactivated automatically and you can make new bookings.
Make sure the account has a working payment method: update your card in the app (Details → User details) or at www.tili.omago.fi.
If it’s urgent, or the payment won’t go through, call customer service on 0201277799.