The Change to Win (CtW) Investment Group today filed a complaint with the Securities and Exchange Commission (SEC) about T-Mobile and some of its recent accounting practices.

CtW Investment Group works with pension funds sponsored by unions affiliated with Change to Win, a labor group that’s gone after T-Mo in the past for alleged false advertising.

According to CtW Investment Group, the way that T-Mobile reports some of its metrics don’t conform to generally accepting account principles (GAAP), and that these non-GAAP reporting may make T-Mo’s financials look better than they are and make comparisons to competitors’ earnings “impossible.”

“The SEC has put companies on notice that they should self-correct non-GAAP abuses, and we do not believe T-Mobile’s latest earnings fixed long-standing problems, and the agency’s intervention is necessary,” said Dieter Waiznegger, CtW Investment Group’s Executive Director.

CtW Investment Group also alleges that T-Mobile grew its income by $122 million from Q4 2014 to Q3 2015 with a change in its accounting estimates. Specifically, T-Mo reduced the amount of money it set aside for credit losses from EIPs, even as the risk of future credit losses grew.

“T-Mobile’s financial reporting and accounting estimates are opaque at best and deceptive at worst. Investors simply do not have the information needed to access risks and back out real quarter-on-quarter or year-over-year growth rates,” added Waizenegger. “The company refuses to give investors a transparent look into its growth and financial health.”

It’s unclear whether or not the SEC will actually investigate T-Mobile regarding its accounting practices.

I reached out to T-Mobile for a response about CtW Investment Group’s complaint, but the company declined to comment.

If you’d like to read CtW Investment Group’s full letter to the SEC, you can find it at the link below.

Source: CtW Investment Group