The California Public Utilities Commission (CPUC) threatened to sanction T-Mobile US, claiming the operator hoodwinked it in testimony regarding a merger with Sprint.

In a public filing, the Commission revealed it could fine the operator up to $100,000 per offence at a hearing scheduled for 20 September to discuss statements executives made in 2019 regarding the future of T-Mobile’s CDMA network.

The Commission accuses T-Mobile bosses of making “false, misleading, or omitted statements” regarding the merger.

It noted the operator’s president of technology Neville Ray previously testified a “need to maintain CDMA service” for customers of MVNO Boost Mobile during a migration period would not impact its 5G build “because T-Mobile planned to use Sprint’s 800MHz spectrum” to serve those users.

Now T-Mobile claims it needs the spectrum for 5G and therefore will shut its CDMA network at the start of 2022.

T-Mobile was required to migrate Boost Mobile customers to Dish Network as a condition of the merger. Those subscribers will be left without mobile service until they find a new provider.

The CPUC filing lists five separate statements T-Mobile allegedly made to win approval of the merger and has now revoked.

These cover pledges around customer migration and continuity of service; use of Sprint’s PCS spectrum; and the timing of shifting customers to Dish Network.

The CPUC was the last regulatory body to approve the merger, issuing a lengthy list of conditions which T-Mobile subsequently challenged.

Dish Network has urged regulators to prevent the CDMA shutdown, with the Department of Justice weighing in last week.