Since this pandemic has caused severe loss for everyone, the touristic sector is the most affected.
This is the reason why the Italian Government has recently published a Decree (Decreto Rilancio) where it is established that no IMU is due in relation to those propertiese which are used for touristic reasons.
In particular the properties that belong to the category D / 2 in the cadastral land registry are not obliged to pay the June tranche, however there is no mention of the second tranche which will be potentially due by the 16th of December 2020.
The D / 2 property category includes:
However there is a condition, meaning that IMU is not due if you are the owner, but also the manager of these properties. Whilst if you are just the manager and not the owner of these type of properties, you will not be entitled to this tax exemption.
Regarding all other properties, it depends on each Municipality decision if to postpone the expiring date until September or not. However this is something that is yet to be decided.
In any case, only who has experienced a high loss due to the health emergency will probably be entitled to this extention. All others need to pay by the 16th of June 2020.
More info about property taxes and fiscal benefits in this link