While OnePlus phones and their lower price points have attracted a following, actually having a carrier partner could garner the company a wider user base in the US. "Getting carrier shelf space is a prerequisite to volume sales in the US," Avi Greengart, an analyst at Global Data, told CNET.

One of CNET's sources did note that OnePlus is still in the midst of getting approval by the carrier, meaning launching with T-Mobile isn't set in stone just yet.