Cuba's state-run telecommunications company, ETECSA, announced on Monday that a malfunction in one of the backup power generators has led to widespread disruptions in the nation's cell phone service. This generator supports a key facility crucial to the country's mobile network.
According to an announcement posted on Facebook by ETECSA, the affected phone numbers begin with the prefixes 52, 509, 598, and 599.
"We inform that due to a malfunction in one of the backup generators supporting major mobile service centers nationwide, phone numbers starting with 52, 509, 598, and 599 are affected. Our specialists are actively working to restore services," ETECSA stated, without providing a specific timeline for when services might be restored.
Unlike previous incidents that were confined to specific regions, this particular failure impacts prefixes on a national level, significantly increasing the number of users left without service.
This issue arose just a day after the National Electric System (SEN) experienced its sixth total blackout of the year, triggered by a failure in 220 kV lines between Matanzas, Santa Clara, and Cienfuegos.
Impact of Cuba's Energy Crisis on Telecommunications
ETECSA's reliance on backup generators is a direct result of the ongoing power crisis in Cuba, marking 2026 as the worst in recent memory. The electricity deficit has reached unprecedented levels: 2,174 MW in May, 2,341 MW on July 10, and 2,315 MW on July 24, with service disruptions occurring around the clock in the latter instance.
This structural instability forces the company to keep its data centers and radio bases operational using its own generators. When these fail, the entire communications network is affected.
Frequent Backup Equipment Failures
ETECSA has a history of recurring failures in its backup equipment. In March 2026, a similar breakdown in Cárdenas, Matanzas, disrupted mobile and landline services in the municipality and nearby areas like Perico, Colón, Los Arabos, and Calimete.
By July 2026, the company publicly acknowledged a general increase in service disruptions, as reported by Radio Rebelde. Alarmingly, nearly 47.5% of mobile radio bases and 56.5% of telecommunications cabinets had been knocked out of service due to power outages affecting the mobile network.
This exposes a critical vulnerability in Cuba's telecommunications infrastructure: ETECSA, the sole company in the sector, lacks sufficient electrical infrastructure to maintain operations during extended outages. The available backup equipment is inadequate or deteriorates without timely replacements.
In August 2025, an assessment in Sancti Spíritus revealed that only 21 out of 70 telephone exchanges in the province had backup generators, leaving more than 288,000 mobile lines vulnerable to any disruption in the power supply.
Understanding the Telecommunications Challenges in Cuba
What caused the recent cell phone service disruption in Cuba?
The disruption was caused by a malfunction in a backup power generator that supports a key facility essential to Cuba's mobile network.
Which phone numbers were affected by this outage?
The affected phone numbers are those beginning with the prefixes 52, 509, 598, and 599.
How is the energy crisis impacting ETECSA's operations?
Due to the ongoing energy crisis, ETECSA relies heavily on backup generators to keep its operations running. When these generators fail, it leads to widespread service disruptions.
What are the long-term implications of this instability for Cuba's telecommunications?
The continued instability and lack of sufficient backup infrastructure expose a significant vulnerability in Cuba’s telecommunications system, affecting service reliability and availability.