The December 31 Sim card registration deadline will not be pushed further, Communications Commission of Kenya chairman Francis Wangusi said yesterday.

He however said the exercise had experienced challenges arising from lack of national identity cards among many mobile users but said the cases will be dealt with individually.

Mobile subscribers are supposed to produce a copy of their national ID card or passport to have their lines registered with their mobile operator.

"This has been a major complication as some of the users have no IDs or are waiting for theirs," Wangusi said on the phone. "But we will deal with such cases as they arise."

He said CCK is engaging the ministry of Immigration to work out this.

Mobile network operators have been on an aggressive media drive to have their subscribers register their lines.

Safaricom says it has so far registered 90 per cent of its users. Essar Telecom said only 34 per cent of its customers have registered.

As of two weeks ago, Wangusi said, Airtel had reported registering about 80 per cent of its subscribers, up from about 50 per cent a few months back. The regulator said it is compiling the total number of lines registered, to be announced by end of the month.

Two years ago, the commission had embarked on the registration but it was unsuccessful since there was no law that compelled operators to switch off unregistered customers. But an amendment to the Kenya Information and Communications Act, 1998 now gives the move legal backing.

By end of September 2010 when the last registration round was put on hold, about 62 per cent out of the then estimated 20 million mobile users then had registered their numbers.

The Sim card registration is targeted at curbing mobile propagated crimes like kidnappings, fraud and hate messages.

The Sim registration process was meant to go hand in hand with the switchoff of counterfeit mobile handsets which was carried out in October.