15. IRB Approach: Treatment of Expected Losses and Provisions
15.1 This chapter discusses the calculation of expected losses (EL) under the internal ratings-based (IRB) approach, and the method by which the difference between provisions (e.g. specific provisions, partial write-offs, portfolio-specific general provisions such as country risk provisions or general provisions) and EL may be included in or must be deducted from regulatory capital, as outlined in the definition of capital rules, articles 2.2.3 and 4.1.4 – Section A of SAMA Guidance Document Concerning the Implementation of Basel III (Circular No. 341000015689, Date: 19 December 2012). The treatment of EL and provisions related to securitization exposures is outlined in paragraph 18.36.
Calculation of Expected Losses
15.2 A bank must sum the EL amount (defined as EL multiplied by exposure at default)associated with its exposures to which the IRB approach is applied (excluding the EL amount associated with securitization exposures) to obtain a total EL amount.
15.3 Banks must calculate EL as probability of default (PD) x loss-given-default (LGD) for corporate, sovereign, bank, and retail exposures not in default. For corporate, sovereign, bank, and retail exposures that are in default, banks must use their best estimate of expected loss as defined in paragraph 16.85 for exposures subject to the advanced approach and for exposures subject to the foundation approach banks must use the supervisory LGD. For exposures subject to the supervisory slotting criteria EL is calculated as described in the chapter on the supervisory slotting approach (paragraphs 13.8 to 13.12). Securitization exposures do not contribute to the EL amount, as set out in in paragraph 18.36.
Calculation of Provisions
Exposures subject to the IRB approach for credit risk
15.4 Total eligible provisions are defined as the sum of all provisions (e.g. specific provisions, partial write-offs, portfolio-specific general provisions such as country risk provisions or general provisions) that are attributed to exposures treated under the IRB approach. In addition, total eligible provisions may include any discounts on defaulted assets. General and specific provisions set aside against securitization exposures must not be included in total eligible provisions.
Portion of exposures subject to the standardized approach for credit risk
15.5 Banks using the standardized approach for a portion of their credit risk exposures (see paragraphs 10.43 to 10.48), must determine the portion of general provisions attributed to the standardized or IRB treatment of provisions according to the methods outlined in paragraphs 15.6 and 15.7 below.
15.6 Banks should generally attribute total general provisions on a pro rata basis according to the proportion of credit risk-weighted assets subject to the standardized and IRB approaches. However, when one approach to determining credit risk-weighted assets (i.e. standardized or IRB approach) is used exclusively within an entity, general provisions booked within the entity using the standardized approach may be attributed to the standardized treatment. Similarly, general provisions booked within entities using the IRB approach may be attributed to the total eligible provisions as defined in paragraph 15.4.
15.7 At SAMA’s discretion, banks using both the standardized and IRB approaches may rely on their internal methods for allocating general provisions for recognition in capital under either the standardized or IRB approach, subject to the following conditions. Where the internal allocation method is made available, the national supervisor will establish the standards surrounding their use. Banks will need to obtain prior approval from their SAMA to use an internal allocation method for this purpose.
Treatment of EL and Provisions
15.8 As specified in articles 2.2.3 and 4.1.4 – Section A of SAMA Guidance Document Concerning the Implementation of Basel III (Circular No. 341000015689, Date: 19 December 2012), Banks using the IRB approach must compare the total amount of total eligible provisions (as defined in paragraph 15.4) with the total EL amount as calculated within the IRB approach (as defined in paragraph 15.2). In addition, article 2.2.3 in the aforementioned rules outlines the treatment for that portion of a bank that is subject to the standardized approach for credit risk when the bank uses both the standardized and IRB approaches.
15.9 Where the calculated EL amount is lower than the total eligible provisions of the bank, SAMA will consider whether the EL fully reflects the conditions in the market in which it operates before allowing the difference to be included in Tier 2 capital. If specific provisions exceed the EL amount on defaulted assets this assessment also needs to be made before using the difference to offset the EL amount on non-defaulted assets.