Under the Local Authorities Rating Ordinance 11 of 1977 (T), a local authority may levy only one general property tax (algemene eiendomsbelasting) per property per financial year. Although article 21(1) refers to "property tax or taxes" in the plural, this refers to the different possible types of general property tax set out in article 21(3), not to multiple levies in the same financial year. Article 26(1) confirms that the amount levied as general property tax is the (single) amount payable for property tax in respect of a particular financial year. Since every general property tax under article 21(3) must be based wholly or partially on land value (terreinwaarde), only one property tax based on land value may be levied per property per financial year. Where a local authority needs to raise additional revenue for exceptional circumstances or emergencies, it must either make provision in its budget or utilize the special property tax provisions in article 24, subject to meeting the requirements of that article.