moving from moto g to moto x4 will i need a new sim?
From the original Moto g to the X4?
Yes, you will need to get a new SIM. The one in your Moto G (again if it’s gen 1, 2 or 3) will need to stay with that phone.
Please note that your Moto G is using RW’s CDMA partner and ordering a new SIM will probably get you the SIM for the GSM partner. Your coverage might be even better then you have now with the GSM SIM, but if not, you can open a ticket and get back to the CDMA coverage.