Are the regions strictly where they're based or where they serve? I've used PCBWay and JLCPCB for projects and had the boardś mailed from China to the US. But c

Are the regions strictly where they're based or where they serve? I've used PCBWay and JLCPCB for projects and had the boardś mailed from China to the US. But can I take it for granted that I could do this with the rest of the suppliers? FWIW both services provided excellent boards, even with an order of only 5 units.