1. Institutions and any parent undertaking and its subsidiaries shall implement the IRB Approach for all exposures, unless they have received the permission of the competent authorities to permanently use the Standardised Approach in accordance with Article 150.
Subject to the prior permission of the competent authorities, implementation may be carried out sequentially across the different exposure classes referred to in Article 147 within the same business unit, across different business units in the same group or for the use of own estimates of LGDs or conversion factors for the calculation of risk weights for exposures to corporates, institutions, and central governments and central banks.
In the case of the retail exposure class referred to in Article 147(5), implementation may be carried out sequentially across the categories of exposures to which the different correlations in Article 154 correspond.
2. Competent authorities shall determine the time period over which an institution and any parent undertaking and its subsidiaries shall be required to implement the IRB Approach for all exposures. This time period shall be one that competent authorities consider to be appropriate on the basis of the nature and scale of the activities of the institutions, or any parent undertaking and its subsidiaries, and the number and nature of rating systems to be implemented.
3. Institutions shall carry out implementation of the IRB Approach in accordance with conditions determined by the competent authorities. The competent authority shall design those conditions such that they ensure that the flexibility under paragraph 1 is not used selectively for the purposes of achieving reduced own funds requirements in respect of those exposure classes or business units that are yet to be included in the IRB Approach or in the use of own estimates of LGDs and conversion factors.
4. Institutions that have begun to use the IRB Approach only after 1 January 2013 or that have until that date been required by the competent authorities to be able to calculate their capital requirements using the Standardised Approach shall retain their ability to calculate capital requirements using the Standardised Approach for all their exposures during the implementation period until the competent authorities notify them that they are satisfied that the implementation of the IRB Approach will be completed with reasonable certainty.
5. An institution that is permitted to use the IRB Approach for any exposure class shall use the IRB Approach for the equity exposure class laid down in point (e) of Article 147(2), except where that institution is permitted to apply the Standardised Approach for equity exposures pursuant to Article 150 and for the other non credit-obligation assets exposure class laid down in point (g) of Article 147(2).
6. EBA shall develop draft regulatory technical standards to specify the conditions according to which competent authorities shall determine the appropriate nature and timing of the sequential roll out of the IRB Approach across exposure classes referred to in paragraph 3.
EBA shall submit those draft regulatory technical standards to the Commission by 31 December 2014.
Power is delegated to the Commission to adopt the regulatory technical standards referred to in the first subparagraph in accordance with Articles 10 to 14 of Regulation (EU) No 1093/2010.