Part 1: Digital Markets Administration Section 105: Extensions: supplementary
This section provides additional detail on how extensions made under section 104 interact with each other, are brought to a close and are calculated.
	Subsection (1) clarifies that both types of extension provided for in section 104 can be applied in the course of any given final offer period or ‘relevant investigation period’, defined at section 104, subsection (8), for SMS investigations, conduct requirement breach investigations, pro-competition intervention investigations. For example, the CMA can extend an SMS designation investigation for up to three months, and also make a "stop the clock" extension as part of that period.
	Subsection (2) clarifies that only one extension of up to three months for special reasons can be made per ‘relevant period’. This restriction does not apply for a "stop the clock" extension which can be applied multiple times.
	Subsection (3) clarifies how the total length of SMS investigations, conduct requirement breach investigations, pro-competition intervention investigations and final offer periods will be calculated, when they have been subject to an extension made under section 104, subsection (1) or section 104, subsection (3). For example, if a 9-month SMS investigation is subject to a 2-month extension under section 104, subsection (3), the final length of the investigation will be 11 months.
	Subsection (4) clarifies that for periods where multiple 103 (3) extensions are active at the same time, they are considered to run concurrently rather than cumulatively. For example, if a 9-month SMS investigation had been extended for two months under section 104, subsection (3), and one month into that extension a further two-month extension under section 104, subsection (3) occurs, then those extensions would run concurrently for one month, and that period of overlap would be ignored when calculating the total length of the extension made. The total length of that investigation would be nine months plus two months for the initial extension, plus one month for the remainder of the second extension, for a total of 12 months.