I.-For each commune, the rate of each of the exemptions from property tax on built-up properties provided for in articles 1382 B, 1382 C, 1382 C bis, 1382 D, 1382 E, 1382 G, 1382 H, 1382 İ, 1383-0 B, 1383-0 B bis, 1383 C ter, 1383 D, 1383 E, 1383 E bis, 1383 F, 1383 G, 1383 G bis, 1383 G ter, 1383 H, 1383 İ and 1383 J, to IV of article 1384 A, to the first and fourth paragraphs of article 1384 B, to III of article 1384 C as well as to articles 1384 E, 1384 F, 1586 A and 1586 B in their version in force on 31 December 2020, is equal to the ratio between:
1° On the one hand, the sum of the products, calculated respectively for the municipality and the department, of the exemption rate by the tax rate applied in 2020 on the territory of the municipality;
2° On the other hand, the sum of the property tax rates on built properties of the municipality and the department applied in 2020 on the territory of the municipality.
II.-For business premises existing on 1 January 2020 and assessed pursuant to Article 1498, for the application of I of this article, the exemption rate is equal, for each premises, to the ratio between:
1° On the one hand, the sum of the products, calculated respectively for the commune and the département, of the tax base for property tax on built-up properties determined in respect of 2020, after application of article 1388, by the product of the exemption and tax rates applied in 2020 on the territory of the commune ;
2° On the other hand, the product of the sum of the tax rates for property tax on built-up properties of the municipality and the département applied in 2020 on the territory of the municipality and the municipal tax base for property tax on built-up properties determined in respect of 2020 after application of Article 1388 and, where applicable, of 3 of I and III of Article 1518 A quinquies.
III.-I and II cease to apply, for an exemption, as soon as the municipality deliberates to modify it pursuant to Articles 1639 A bis or 1640.
However, in the event of application of the first paragraph of this III, the exemptions applicable in execution of deliberations taken by the communes and departments, as well as the exemptions applicable in the absence of deliberations to the contrary adopted by these authorities, in application of articles 1382 C bis, 1382 D, 1383-0 B, 1383-0 B bis, 1383 C ter, 1383 D, 1383 E, 1383 F, 1383 G, 1383 G bis, 1383 G ter, 1383 H, 1383 İ and 1383 J, in IV of article 1384 A, in the first and fourth paragraphs of article 1384 B, in III of article 1384 C as well as in articles 1384 E, 1384 F, 1586 A and 1586 B in their version applicable on 31 December 2020, are maintained for their duration and quota initially provided for.
IV.-I and II do not apply to the establishment of the tax bases for the taxes provided for in Articles 1520 and 1530.