Any process in which the SREBP-SCAP complex is maintained in the endoplasmic reticulum and prevented from moving elsewhere. The SREBP-SCAP complex is formed by the association of sterol regulatory element binding protein (SREBP) and SREBP-cleavage-activating protein (SCAP). In the absence of sterols, the SREBP-SCAP complex is packaged into COPII vesicles and travels to the Golgi apparatus to be processed. In the presence of sterols, the complex binds ER-resident proteins such as INSIG, which retain the complex in the ER.