The Approved Refiner and Consolidator Scheme (ARCS) is administered by the Inland Revenue Authority of Singapore. You may refer here and the e-Tax Guide "GST: Approved Refiner and Consolidator Scheme" for more information on the ARCS and its requirements.

As an approved person under the ARCS, you or your appointed Declaring Agent (DA) should obtain an In-Non-Payment (IPT) "GST Relief (GTR)" permit instead of a MES permit if you are importing Investment Precious Metals (IPMs) into Singapore.

Please refer here for import permit requirements for IPMs and the information that should be declared in the permit application.