Postal orders for payment of real estate tax are in most cases sent annually to taxpayers, who are natural persons, or to legal entities, who do not have a data box set up. The Financial Administration has issued the information on how it will look this year:

• To natural persons, who do not have a data box of a natural person or a data box of an enterprising natural person set up, are not registered for payment of tax using SIPO (direct debit of multiple payments, service provided by Czech Post) and are not registered to have data for tax payment sent to their e-mail, a tax postal order marked Postal order A (Poštovní poukázka A) is being sent.
• To legal entities, who do not have a data box set up, a standard postal order of type A is being sent.
• To natural persons, who have a data box of a natural person or a data box of an enterprising natural person set up, are not registered for payment of tax using SIPO (direct debit of multiple payments) and are not registered to have data for tax payment sent to their e-mail and the amount of tax has not been announced to them by means of an adjustment notice, the Information about a tax obligation is sent to their data box of a natural person or a data box of an enterprising natural person, instead of a postal order.
• For legal entities, who have a data box set up, and the amount of tax has not been announced to them by means of an adjustment notice, the Information about a tax obligation is also sent to their data box instead of a postal order. If a taxpayer registers to have data for tax payment sent by email, instead of a postal order he will annually receive an email message to the email address he specifies, before the first tax instalment is due, and in the attachment, he will receive complete information for payment of tax in the PDF format.

You can read more detailed information here.