(15)The requirements in Prudential Standard CPS 226 for the calculation of initial margin should be considered equivalent to the requirements set out in Delegated Regulation (EU) 2016/2251. In a manner similar to the standardised method for the calculation of the initial margin set out in Annex IV to Delegated Regulation (EU) 2016/2251, Prudential Standard CPS 226 allows for the use of a standardised model equivalent to the one laid down in that Annex IV. Alternatively, internal or third party models can be used under Prudential Standard CPS 226 to calculate the initial margin where those models contain certain specific parameters equivalent to those set out in Delegated Regulation (EU) 2016/2251, including minimum confidence intervals and margin periods of risk and certain historical data, including stressed periods. APRA covered entities must apply to APRA for approval to use an internal or third party model and ensure that an independent review of this model is carried out before the approval is sought.