Nairobi — Safaricom has switched off 800,000 unregistered SIM cards in a phased exercise that seeks to comply with the newly published government regulations on mandatory SIM card registration.

The first phase of the switch off was conducted on Thursday evening after the system was updated with registrations that came in on December 31, 2012.

Safaricom CEO Bob Collymore said that they have been doing their best to update the electronic records after the last minute rush that saw a huge number of customers register their SIM cards between December 31, 2012 and January 3, 2013.

"We are refining the switch off process and it will continue into the weekend and those affected by the blocking will be unable to make calls or utilise any of our services until their SIM cards are registered," he said.

"Safaricom being the largest mobile operator has invested heavily in awareness campaigns and has so far registered over 85 percent of its subscriber base," he added.

Unregistered subscribers who get switched off are advised to visit Safaricom shops and authorised dealer outlets to start the process of reinstatement.

Safaricom also announced that it registered record-breaking customer transactions on its M-PESA service on Christmas eve.

According to Collymore, the total M-PESA customer activities recorded from midnight of December 24 stood over eight million transactions compared to 5.6 million transactions on Christmas eve in 2011, representing a 30 percent growth.

He explained that between 11am and 8pm on that day, Kenyans made over 10,000 transactions per minute, adding that it is worth noting that no other mobile money transfer service in the world has ever recorded this level of transactions.