Can you use indoor wire outside in conduit?

It's important that you follow National Electrical Code (NEC) rules when running an indoor wire through a conduit outdoors. You need to ensure that the conduit is buried deep enough within the ground: 24 in. of earth cover for a UF cable, 18 in. of cover for a PVC conduit, and 6 in. of cover for RMC and IMC conduits. For those who live in the United States, it's best to call 811 before installing any wiring outside to ensure you meet the code.