Deutsche Telekom's chief executive is preparing for a contested regulatory fight to land a US mega-merger, according to a Financial Times report this week.

The Bonn-based incumbent, which controls just over half of T-Mobile US through its majority stake, has signalled internally that the next phase of the transaction will be contested rather than routine.

People familiar with the group's thinking, cited by the FT, describe the work ahead as defence rather than closure. In US telecoms, a deal agreed between boards can still be unwound at the Department of Justice or the Federal Communications Commission. Both agencies have shown through 2024 and 2025 that they will litigate combinations that move spectrum concentration or retail share across their internal thresholds.

What kind of "battle" is DT preparing for?

Two tracks, on the public reporting. The first is regulatory clearance, where a second request from the DOJ Antitrust Division and a formal FCC hearing are the default expectation for any large wireless transaction. The second is commercial: financing structure, board-to-board negotiation with the counterparty, and the management transition that follows announcement. The FT account implies DT is now staffing both simultaneously.

Why does this move the parent?

Because the exposure runs through T-Mobile US, which DT no longer fully consolidates financially but which now drives the bulk of group operating profit. T-Mobile US ended 2024 with roughly 86 million postpaid phone customers and a market capitalisation that closed the year above $250 billion. Any transaction that folds another wireless operator, or a meaningful cable-mobile combination, into that base shifts the parent's math materially. The larger the deal relative to T-Mobile US's enterprise value, the harder the integration work that Bonn has to underwrite.

A skeptical reading

The FT piece withholds the three figures that determine the regulatory test: the counterparty, the headline price, and the form of consideration. A "mega-merger" in this segment typically denotes enterprise value above $20 billion, and the recent US telecoms precedent band has run between roughly $30 billion and $60 billion on major wireless transactions. Without naming the target, neither the DOJ nor the FCC's review timeline can be estimated.

DT has the deepest recent playbook to draw on. The Sprint-T-Mobile combination announced in 2018 and closed in April 2020 took more than 24 months, required a $26 billion stock-and-cash restructure, and forced divestitures to DISH Network on the prepaid side and on a tranche of 800 MHz spectrum before the DOJ would consent. That fight was won with a remedy package. DT is now reportedly preparing for a similar fight, with the harder constraint that the available low-band spectrum in the US market has since narrowed.

Where the leverage sits

T-Mobile US holds more than 320 MHz of usable spectrum nationwide and was the only major US carrier to add postpaid phone net additions in every quarter of 2024, on its own disclosures. That scale gives DT room to package divestiture commitments — the same lever that bought Sprint-T-Mobile over the line — without breaking the combined business model. It also gives DT counter-bid optionality if a competing bid emerges, a scenario the FT does not address but that any board would model.

Outlook

DT's investor-day guidance has pointed to T-Mobile US driving the majority of group revenue growth through 2027, which makes any incremental US consolidation financially weightier than the parent's 2020 framing would have suggested. On the FT's reading, the work to close — not announce — the next US transaction is already underway.