Companies in the Ibex 35 have established the basic pillars of transparency in their regulatory compliance systems, but they still fail to substantively explain how they work in practice, what results they produce, and what improvements they introduce. This is the main conclusion of the 2026 edition of the report Transparency and good governance of compliance practices of compliance of the companies in the Ibex 35, prepared by the Haz Foundation with the support of the Spanish Compliance Association (Ascom).
The study grants the listed companies a global compliance rate of 62%. By categories, thirteen companies reach the level of "transparent" (over 65% compliance), twenty-one are classified as "translucent", and only one, ArcelorMittal, remains in the "opaque" group (less than 32%). The evolution since the first edition in 2021 is notable: then only 8% of the listed companies were transparent and 31% were opaque.
The podium of transparency in compliance is shared by ACS, Iberdrola, and Inditex, tied at the top with 31 points out of 34 (91% compliance). They are closely followed by Enagás, with 30 points (88%), and Acerinox, with 27 (79%).
The data confirms that the formal structure is practically widespread. 100% of the listed companies publish their ethical code and report on their main compliance risks and preventive measures. Likewise, 94% detail the management procedure of their ethical channel, 91% fully explain their compliance programme, and 86% identify the person responsible for the function.
From formal existence to real effectiveness
To adapt to the new ISO 37302:2025 guide, the Haz Foundation has tightened two of its seventeen indicators in 2026 with the aim of measuring the real effectiveness and continuous improvement of the systems. In this area, the main shortcomings of corporate governance arise: although 71% of firms detail the supervisory work of the audit committee, only ACS is certified to evaluate the effectiveness of the system before the board of directors, while 83% do not meet the standard.
A similar gap is observed in the management of the ethical channel. Although 72% adequately reports on the complaints received, only 6% —only Iberdrola and Inditex— fully complies with the new indicator on actions derived from such communications, with most limiting themselves to reporting sanctions without explaining the lessons incorporated into their controls.
Pending subjects in the board
The analysis also highlights gaps in autonomy, resources, and accountability of the compliance function. Only 6% of companies fully detail the budget and staff assigned to this unit, and only 34% fully certifies the intervention of the board or one of its committees in the appointment and dismissal of its head. Furthermore, although general awareness has risen fourteen points to 74%, specific training for the board remains lagging: only 8% fully complies with this indicator due to the lack of public information on content and attendance.
"The companies in the Ibex 35 have responded very well to the demands of this standard: in five years, opacity has decreased from 31% to 3%. Now it is time to take a step forward and provide information that allows understanding the effectiveness of their compliance systems. The challenge is to ensure that the reporting explains management better: what is reviewed, what is learned, and what decisions are made to improve," says Javier Martín Cavanna, director of the Haz Foundation and co-author of the report.