Simba Telecom’s parent Tuas Limited told the Australian Securities Exchange on Monday that Singapore’s Infocomm Media Development Authority has issued a notice to show cause over alleged misuse of radio spectrum, escalating a probe that already helped scupper Simba’s planned takeover of rival M1. IMDA has not made final findings, but the notice asks why the mobile operator should not face penalties that could include spectrum cancellation, licence suspension or fines of up to S$1 million or 10% of relevant annual turnover, whichever is higher.
What IMDA alleges
According to Tuas’s filing, the authority alleges Simba deployed dynamic spectrum sharing at about 133 sites during intermittent periods in 2022 and 2023, using 2100 megahertz spectrum for both 4G and 5G when its assignment covered 5G only. Dynamic spectrum sharing lets 4G and 5G share the same frequency block; in Singapore, carriers may use only the bands IMDA assigns. Regulators also allege Simba transmitted in the 2340–2360 MHz band at roughly 92 sites between 2023 and 2026 without authorisation.
IMDA contends those deployments were intentional and approved by Simba’s senior management. Additional allegations include rolling out indoor 5G radio equipment at two locations in 2023 before approval was granted on 14 November that year, and deliberately failing to comply with a document production order. The authority said it is concerned about governance and compliance culture at the fourth national mobile network operator.
Stakes for Singapore’s telecom market
Spectrum in Singapore is tightly rationed: IMDA assigns frequency blocks that carriers may use exclusively, and unauthorised sharing can interfere with rivals’ networks and undermine auction outcomes. Simba must respond by 16 November 2026. Until then, the company said it does not intend to comment beyond the ASX disclosure.
Channel News Asia and The Straits Times noted that unauthorised spectrum use first surfaced in May and contributed to the collapse of Simba’s roughly S$1.4 billion bid for M1. A licence suspension or spectrum clawback would be extraordinary in a market where consumers expect four nationwide carriers to compete on price and 5G coverage.
What investors are watching
Tuas shares trade on the ASX, meaning regulatory action in Singapore moves Australian shareholder value. IMDA’s notice lists potential remedies under the Telecommunications Act and radio-communications regulations, including written orders to secure licence compliance and added governance conditions. For subscribers, service continuity is the immediate question; for the industry, the case will signal how aggressively Singapore punishes intentional spectrum breaches when regulators say senior leaders signed off, as distinct from honest engineering mistakes.
Tuas told investors it will file its response before the 16 November deadline and that no regulatory decision is final until IMDA completes its review. Analysts covering Singapore telecoms said a financial penalty is more likely than a full licence cancellation, but any spectrum clawback could force Simba to rebalance its 5G coverage map against Singtel, StarHub and M1.