Simba Faces Licence Risk as IMDA Alleges Intentional Spectrum Misuse Approved by Senior Management

Six allegations put Simba's operations under scrutiny

Singapore's Infocomm Media Development Authority (IMDA) has asked Simba Telecom to answer six allegations, including that senior management approved intentional use of radio frequencies the operator was not authorised to use. The allegations cover spectrum use at about 133 sites in 2022 and 2023 and about 92 sites between 2023 and 2026.

Simba received the notice on October 23, 2026, and has until November 16 to respond. Its Australian parent, Tuas, disclosed the details in an Australian Securities Exchange filing on October 26. Possible action includes fines, suspension or cancellation of spectrum rights, and suspension or cancellation of its telecommunications licence.

The case also covers the installation of indoor 5G equipment before approval, alleged deliberate failure to produce documents, and concerns about how Simba is managed and follows regulatory rules. IMDA is considering additional licence obligations to address those concerns and prevent similar conduct.

Tuas said IMDA had reached no conclusion on whether regulatory action should be taken or what form it might take. A notice to show cause gives Simba an opportunity to answer the allegations and explain why the proposed action should not follow.

Two spectrum allegations involve different restrictions

IMDA alleges that Simba deployed dynamic spectrum sharing at about 133 sites for intermittent periods during 2022 and 2023. The technology allowed the operator to use the 2,100 megahertz (MHz) band for both 4G and 5G services, although its permission covered only 5G.

Dynamic spectrum sharing lets different generations of mobile technology use the same frequency band. In this part of the case, the restriction concerned which technology Simba could operate within a band it had permission to use.

IMDA's second spectrum allegation concerns frequencies from 2,340 MHz to 2,360 MHz. The regulator alleges that Simba used this band without authorisation at about 92 sites for intermittent periods between 2023 and 2026. This concerns access to the frequencies themselves.

Radio spectrum consists of electromagnetic waves that carry mobile calls and internet data. IMDA assigns operators particular bands and sets conditions for their use. Those permissions determine both where an operator can transmit and, where specified, the services it can provide.

Senior management approval is central to the case

IMDA alleges that both forms of unauthorised spectrum use were intentional and approved by Simba's senior management. That brings decisions inside the company into the investigation alongside the technical operation of its network.

Simba had already acknowledged in September 2026 that it used spectrum beyond the limits permitted by the regulator. Management attributed the unauthorised use of spectrum in the 2,300 MHz range to a combination of hardware and software issues, without giving further details.

The October notice now requires Simba to address the allegation of deliberate conduct approved at a senior level. Its response will therefore need to address management decisions as well as the earlier technical explanation.

Tuas, Simba's parent company, said it intended to respond by the deadline. In its exchange filing, the company explained why it would not comment further:

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.

Equipment approval and document production also questioned

IMDA separately alleges that Simba deployed indoor 5G radio access network equipment at two locations in 2023 before receiving authorisation. Approval was granted on November 14 that year. Radio access equipment provides the wireless connection between mobile devices and an operator's network.

The regulator also alleges that Simba did not fully comply with a production order, a formal instruction to hand over documents. According to the notice disclosed by Tuas, the failure to produce the documents was deliberate and intentional.

IMDA's concerns extend to Simba's governance and compliance culture. Governance concerns how a company is directed and supervised. Compliance culture concerns how consistently its people follow legal requirements and licence conditions in their daily decisions.

The proposed additional regulatory obligations would target those management concerns. Simba consequently faces questions about three connected areas: how its network was configured, how decisions were approved, and how the company responded when the regulator sought information.

What penalties could IMDA impose?

IMDA is considering financial penalties of up to 10 per cent of the annual turnover of the relevant part of Simba's business or S$1 million, whichever is higher. Turnover means revenue earned by a business, rather than the profit left after expenses.

The possible sanctions also reach beyond money. IMDA may suspend or cancel Simba's spectrum rights, suspend or cancel its telecommunications licence or part of it, shorten the licence period, or impose further obligations to address governance deficiencies.

Spectrum rights and an operating licence perform different jobs. Spectrum rights give an operator permission to use particular airwaves. A telecommunications licence authorises its operations under specified conditions. Action against either could affect Simba's ability to provide services.

IMDA said Simba would have an opportunity to respond to its investigation findings. The next stated deadline is November 16; no date has been given for a final enforcement decision.

Singapore's safeguards focus on interference and service continuity

The Ministry of Digital Development and Information (MDDI) explained the existing safeguards in its July parliamentary response, dated July 7, 2026. It answered a question from Associate Professor Terence Ho about preventing unauthorised spectrum use and whether safeguards would be strengthened following the Simba probe.

MDDI said IMDA conducts regular technical checks and monitors mobile network operators, concentrating on preventing interference and disruption to approved wireless and mobile services. Where interference is detected, IMDA works with affected parties to minimise disruption and takes enforcement action where appropriate.

The ministry explained why operators must obtain approval before using frequencies outside their assignments:

Any use of spectrum beyond the assigned bands without IMDA's prior approval is a serious matter because it can cause interference to other services and allow operators to gain an unfair advantage over their competitors.

For subscribers, the ministry gave a direct commitment: IMDA would ensure Simba continued to meet its licence obligations and service level commitments during the investigation. That places responsibility for maintaining service on the operator while the regulatory process continues.

How the investigation disrupted the M1 acquisition

Simba's regulatory troubles have already affected its expansion plans. Tuas proposed buying M1's telecommunications business in August 2025 in a deal valued at S$1.43 billion. The acquisition would have combined two of Singapore's four mobile network operators.

IMDA suspended its assessment of the proposed transaction in May 2026 after identifying possible unauthorised spectrum use. The regulator said the investigation's findings could affect its assessment of the acquisition. The deal was subsequently terminated after its completion deadline passed.

The main developments span more than a year:

• August 2025: Tuas proposed the acquisition of M1's telecommunications business.
• May 18, 2026: IMDA publicly disclosed possible unauthorised spectrum use by Simba; its assessment of the M1 transaction was halted in May.
• July 7, 2026: MDDI explained spectrum monitoring safeguards and subscriber service commitments in Parliament.
• September 2026: Simba acknowledged spectrum use beyond permitted limits. Keppel also resumed discussions with StarHub about a potential M1 transaction.
• October 23, 2026: IMDA sent Simba the notice to show cause.
• October 26, 2026: Tuas disclosed the six allegations and possible regulatory actions.
• November 16, 2026: Simba's response is due.

Keppel's renewed discussions with StarHub put M1 back into talks with another potential partner. StarHub and M1 had previously discussed a possible combination in 2024, before Simba made its offer.

Tuas shares fall as investors assess the risk

Tuas shares traded at A$1.21 at 9.50am on October 26, down from the previous close of A$1.81. That was a decline of A$0.60, or about 33.1 per cent. The shares also traded as low as A$1.09, a fall of about 40 per cent from the same previous closing price.

The market reaction came as investors learned that the possible consequences included restrictions on the permissions Simba needs to operate, alongside financial penalties. Those risks affect a business that had recently been preparing for a major acquisition.

Simba's latest annual earnings had risen 277 per cent to S$26 million. Its mobile average revenue per user, commonly called ARPU, was S$9.42. ARPU measures the average revenue generated by each user over the reporting period used by the company.

Simba entered Singapore's market as TPG Telecom about a decade ago and competed with plans costing S$10 a month or less. Its growing subscriber base helped support revenue, including payments associated with connecting calls between networks, while revenue per user remained modest.

What matters for customers and the company now?

Simba's immediate task is to submit its response by November 16. The company must address allegations covering two spectrum bands, management approval, equipment deployment, document production and the regulator's wider concerns about governance.

Customers have a different immediate concern: continued access to their mobile services. MDDI's stated position is that Simba must keep meeting its service commitments while IMDA completes its process. Licence suspension or cancellation is among the actions under consideration, rather than an announced instruction to stop operating.

The investigation also places Simba's recent financial growth beside a broader business risk. The company reported rising earnings, but the notice concerns the regulatory permissions on which its network depends. Its abandoned M1 acquisition has already shown how the spectrum investigation can affect plans beyond day to day operations.

IMDA's decision will turn on its assessment after Simba has had the chance to answer. The actions under consideration range from financial penalties and additional obligations to restrictions on spectrum rights and the operating licence.

Key Points

• IMDA issued Simba a notice setting out six allegations, with a response due on November 16, 2026.
• The spectrum allegations concern about 133 sites in 2022 and 2023 and about 92 sites between 2023 and 2026.
• IMDA alleges intentional spectrum misuse approved by senior management and deliberate failure to produce documents.
• Possible action includes fines, additional licence obligations, and suspension or cancellation of spectrum rights or the telecommunications licence.
• The investigation disrupted Simba's proposed S$1.43 billion acquisition of M1, which was later terminated.
• MDDI has said IMDA will ensure Simba continues meeting its licence obligations and service commitments during the investigation.
• Tuas says IMDA has not reached a final conclusion on enforcement action.