Mobile service providers have started the process to block more than two and half crore active mobile subscriptions as of zero hour today, for the users' failure to complete biometric re-registration as per government decree.

The unverified SIMs will be barred from making calls immediately; however, the operators will need some time to block incoming activity of the subscribers, due to the sheer numbers as well as some technical issues, telecom officials said.

Even if operators blocks 10 to 12 connections every second, they can only manage up to 10 lakh connections a day, a senior telecom executive said.

It will take time to block each subscriber's incoming calls, which has to be done individually for each, due to the technicalities involved, Ekram Kabir, vice president of Robi, the local market's third largest mobile operator, told The Daily Star.

Operators will block outgoing calls from the numbers immediately, the officials said.

Mobile companies have already notified the Bangladesh Telecommunication Regulatory Commission of their technical challenges.

As of yesterday evening, the telecoms had re-verified some 10.85 crore SIMs out of the 13.19 crore connections currently active in the sector.

Of that, market leading Grameenphone had re-verified some five crore against their 5.69 crore subscriber base, market sources said.

Banglalink checked 2.72 crore out of its 3.2 crore total users; Robi verified two crore of 2.76 crore total clients, and Airtel re-registered 72 lakh of its 1.01 crore users.

Teletalk is yet to register some 23 lakh out of its total 44 lakh active connections, while about 5.5 lakh of total 7.8 lakh SIMs of Citycell are still unverified.

The telecom regulator on Monday declared that all blocked users can easily re-open their SIMs by completing biometric registration within the next fifteen months. After that, the operators can resell the still unregistered numbers after issuing a public notice for three months, reads an order signed by Mohammad Zulfikar, director of systems and services at BTRC.

From now, all SIM re-registrations and re-sales will be subject to taxation, the BTRC said.

Meanwhile, both the market leader and the smallest operator had sought more time from the regulator to re-register their data SIMs, but have been denied.

In a letter on Monday, GP said they are yet to re-register 26 lakh data SIMs.

Around 50 lakh of the total unregistered SIMs are designated data SIMs and blocking those will cause a big setback to the data business of the telecoms.

Currently, there are 5.87 crore active mobile data connections in the country, according to the BTRC.

Mobile operators are looking at about Tk 600 crore in revenue loss from blocking the active but unregistered data subscriptions, which will also cut into the government's revenue, they said.

The government made biometric re-registration mandatory for all mobile connections on December 16 last year, with the first deadline set for April 30. The window was later extended by a month, and the process finally closed yesterday.

Subscriber authentication will enable better security for mobile financial services and help to curb illegal call termination, which will benefit the telecommunication sector, analysts have said.