Owners on the Premium plan can upgrade to the Superior plan at any time. Since the payment of the publication fee go hand in hand with the payment of the insurance fee, there will be a regulation at the moment of the upgrade. For example: An owner who is on a Premium plan and has yearly payments from March until March the next year can easily upgrade to a Superior plan in for example August. His new Superior plan will run from August until August. He will receive a credit note for the remaining 7 months of his Premium plan, and he will receive in invoice for his new Superior plan for 12 months.
We do not encourage people to change from a Partner plan to a Premium plan. There is really no point of doing this. Especially individual owners should choose the Premium plan immediately. They are not charged the publication fee until there is a booking anyway, and they can cancel the intermediation contract at any time. Owners on a Premium plan are likely to receive much more bookings faster than owners on a Partner plan.
In countries where the Premium and Superior plan is not available owners can not upgrade their Partner plan. And in countries where the Superior plan is not available owners can not upgrade their Premium plan.