Simba Telecom faces licence risk as IMDA alleges deliberate spectrum misuse

Singapore's Infocomm Media Development Authority (IMDA) has put Simba Telecom's licence on the line, serving a show cause notice that alleges the operator ran 4G traffic on 5G-only spectrum at 133 sites — with senior management's approval.

The notice gives Simba until 16 November 2026 to explain and refute six allegations. The potential penalties read like a regulator's full toolkit: a fine of S$1 million (US$780,896) or 10% of the annual turnover of the relevant business line, whichever is higher, plus possible suspension or cancellation of spectrum rights, reduction of licence validity, or outright cancellation of the telecoms licence itself.

Parent company Tuas disclosed the probe in a filing to the Australian Securities Exchange on Monday. The IMDA, it said, has not yet decided whether to act, or how.

What exactly is Simba accused of?

The six allegations cluster around spectrum the operator wasn't licensed to hold. The most substantial: dynamic spectrum sharing of the 2100MHz band for both 4G and 5G at 133 sites, for intermittent periods between 2022 and 2023, when Simba's authorisation covered 5G use only.

The list continues:

• Use of the 2340-2360MHz band at 92 sites, intermittently, between 2023 and 2026, without any authorisation at all.
• Pre-empting approval to deploy 5G indoor radio access network equipment at two locations in 2023.
• Incomplete compliance with an IMDA production order — a failure the regulator reportedly characterises as deliberate and intentional.
• Broader deficiencies in the company's governance and compliance culture.

The IMDA's position on the first two is blunt: both instances were intentional and approved by senior management. That framing matters. Unlicensed transmission is one thing; management sign-off turns a compliance lapse into a governance question.

Dynamic spectrum sharing itself is standard engineering — operators use it to serve 4G and 5G devices from the same carrier. The problem here isn't the technology. It's that Simba's 2100MHz rights covered 5G, and 4G traffic allegedly rode along anyway.

How did the case surface?

The unauthorised use came to light in May, when the IMDA suspended its review of Simba's proposed S$1.43 billion ($1.12 billion) acquisition of M1 to investigate. That investigation killed the deal. Keppel, which holds a controlling interest in M1, is now in talks with StarHub about a possible sale instead.

So one licence dispute has already reshaped Singapore's M&A queue. M1's fate now runs through StarHub rather than Simba, pending whatever Keppel and StarHub agree.

Tuas, for its part, is keeping its commentary to a minimum. "Simba intends to respond to the show cause notice," the company said in its ASX filing. "As the matter remains under consideration by the regulator and no findings have been made or confirmed, Tuas does not intend to provide further comment on the matters raised in this announcement."

A fair posture, legally. It leaves the substance entirely to the regulator's timeline.

What happens next?

The clock runs to 16 November 2026. After Simba responds, the IMDA must decide whether to impose any of the measures it has outlined — financial penalty, spectrum suspension, licence curtailment — or none of them.

A fine of S$1 million or 10% of relevant turnover would sting. Suspension or cancellation of the licence itself would be something else: a fourth mobile operator removed from a small market mid-contract, and a signal that Singapore's regulator treats spectrum boundaries as hard edges rather than negotiating positions.

For now, no findings stand confirmed. What stands is the deadline, the six allegations, and an M1 deal that has already gone elsewhere.