Article 13
1.
For Member States that have not adopted the euro, the value of the euro in national currencies to be applied to the value of the levels of taxation shall be fixed once a year. The rates to be applied shall be those obtaining on the first working day of October and published in the Official Journal of the European Union and shall have effect from 1 January of the following calendar year.
2.
Member States may maintain the amounts of taxation in force at the time of the annual adjustment provided for in paragraph 1 if the conversion of the amounts of the level of taxation expressed in euro would result in an increase of less than 5 % or EUR 5, whichever is the lower amount, in the level of taxation expressed in national currency.