Exhibit 23(g)3

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statement on FormS‑3 (No. 333-212328) and on Form S-8 (Nos. 333-26963 and 333-154965) of Southern Company Gas of our reportdated February 14, 2018 relating to the financial statements of Southern Natural Gas Company, L.L.C., which appears in this Form 10‑K of Southern Company Gas.

/s/ PricewaterhouseCoopers LLP

Houston, Texas

February 14, 2018