Around here the rule in some places is 5' and some 6',,,,but that's for new construction.
If you're upgrading from a 100 to a 200, and leave the meter location, and panel location, the same as they were, you can grandfather in. I've set them 15' deep in a house. I'm quite sure my competition bid it for service disco and SER, so I get the job:grin:
just how do you get "grandfathered" if you have replaced everything, that sounds NEW to me.