The Basel FRTB specification includes a requirement that every desk (even IMA desks) must have its capital calculated under the standardised approach. The reasons are as follows:

• If an IMA desk fails back testing or P&L attribution tests the desk must revert to the standardised approach.
• If an IMA desk is in the Amber zone for P&L attribution a capital surcharge is calculated. This surcharge requires the desk's standardised capital (SAga) as an input to the surcharge formula.