It is different on most venders, so you need to Ask/see what they are doing at each place.
To some a preinlet stock has the barrel channel cut, the RR hole drilled, butt shaped & that's it. You have to do the lock inlet, trigger inlet, buttplate, forestock, sideeplate, RR & entrypipes, etc. Some do 90% of the lock inletting, some do 50%, etc. Just depends on the vender. Some of the venders have web sires & show you what theirs look like.