I agree with John, I have seen a lot of different distances on the inside of the house where the main service is located. The AHJ will have the final word on it. If I was inspecting the job, I would want it as close as possible, as safe as possible or encased in concrete. I have seen where a cable would drop from the ceiling down 4 feet, but it was all above 6 foot high so that you couldn't reach the service cable. I have also made guys install pipe in concrete when they ran a service inside the building because the pipe was subject to physical damage. It is a hard call to make. Get the AHJ out there before you do the job, and I think everyone will be happier.