Part 1: Digital Markets Enforcement of conduct requirements Section 26: Power to begin a conduct investigation
This section provides when and how the CMA can begin an investigation into a suspected breach of a conduct requirement (a conduct investigation). The CMA can use its investigatory and enforcement powers where a suspected breach has taken place during a period of designation or while transitional provisions under section 17 are or have been in place.
	Subsection (1) outlines the threshold that the CMA must meet to open a conduct investigation. The CMA will decide on the basis of available evidence, such as that arising from complaints submitted by third parties or from the CMA’s market monitoring, whether it has reasonable grounds to suspect that an undertaking has breached a conduct requirement.
	Subsection (2) explains that a conduct investigation concerns both whether a breach of the conduct requirements has occurred and, if it has, what action the CMA should take in relation to the breach - for example, the imposition of penalties and/or enforcement orders.
	Subsections (3) and (4) outline the requirement for the CMA to give a notice to the undertaking about the investigation (a conduct investigation notice) and set out the content required for that notice. A conduct investigation notice marks the start of the investigation and of the statutory conduct investigation period, which is a period of six months (see section 30(2)), although it can be extended in certain circumstances (see section 104).
	Subsection (6) requires that the CMA must, as soon as reasonably practicable after giving a conduct investigation notice, publish a summary of the notice. This is to make those who may be interested aware of the ongoing investigation and could summarise the contents of the notice provided to the relevant designated undertaking, while allowing the CMA to redact some information for confidentiality purposes.