1. The operator or aircraft operator shall notify the competent authority of any proposals for modification of the monitoring plan without undue delay.

However, the competent authority may allow the operator or aircraft operator to notify modifications of the monitoring plan that are not significant within the meaning of paragraphs 3 and 4 by 31 December of the same year.

2. Any significant modification of the monitoring plan within the meaning of paragraphs 3 and 4 shall be subject to approval by the competent authority.

Where the competent authority considers a modification not to be significant, it shall inform the operator or aircraft operator thereof without undue delay.

3. Significant modifications to the monitoring plan of an installation include:

(a) changes to the category of the installation where such changes require a change to the monitoring methodology or lead to a change of the applicable materiality level pursuant to Article 23 of Implementing Regulation (EU) 2018/2067;

(b) notwithstanding Article 47(8), changes regarding whether the installation is considered an 'installation with low emissions';

(c) changes to emission sources;

(d) a change from calculation-based to measurement-based methodologies, or vice versa, or from a fall-back methodology to a tier-based methodology for determining emissions or vice versa;