25kV service from wye transformer - am I required to carry the neutral?

[jdcpe17]

I have a utility transformer 138kV WYE 4W : 25kV WYE 4W , feeding my site. Am I required to carry the neutral even though I have no single-phase loads? Thank you.

 

[Hv&Lv]

Why wouldn’t you use concentric neutral cable anyway and just take it with you.
It’s probably cheaper anyway.