The global mobile phone industry is trying to rein in the rapid worldwide spread of illegitimate handsets by introducing a stricter regime for the allocation of handset identification numbers.

The move comes as unlicensed Chinese handset manufacturers have started flooding the world market with exports in a competitive threat to global mobile phone brands.

The GSM Association, a group of operators and equipment makers involved with the GSM mobile standard, used mostly in Europe, has started charging handset makers for international mobile equipment identity, or IMEI, numbers.

It hopes to discourage illegal trade in the numbers and thus make it harder for illegitimate manufacturers to get their hands on them.

“The GSMA is also taking this opportunity to begin addressing the issue of fake and counterfeit IMEI numbers in the market, which is known to be a serious concern for all legitimate device manufacturers,” said the association.

IMEI numbers are allocated to manufacturers to identify legitimate handsets and prevent their illegitimate use. But widespread abuse in the allocation of the codes, driven by demand from “whitebox” handset makers, has made that system inefficient, say industry experts.

Whitebox handsets include, but are not exclusively, counterfeits of branded handsets. Research group iSuppli said this month that shipments of whitebox handsets, thousands of which are made in unlicensed tiny garage workshops in the Chinese city of Shenzhen, were set to jump 44 per cent to 145m units, or 13 per cent of the global legitimate handset market, this year. Exports were expected to soar to 101m units from 60m units in 2008, said iSuppli.

Whitebox manufacturers enjoy a cost advantage as they do not do any product safety tests and do not offer any guarantees or after-sales service. But as they lack business licences, they are unable to acquire IMEI numbers legally.

According to analysts, these manufacturers use numbers copied from legitimate devices or bought from other handset makers.

“Some carry 00000 as the last five digits and others 12345. Still others will be copied from Nokia and duplicated,” said Attilio Zani, a director of the GSMA. “While some countries, such as India, are very keen on their national security and have thus insisted that an IMEI must never be copied, enforcement has been less strict in other countries,” he said.

Mr Zani said the association hoped that charging for the codes would make it less attractive for handset makers, regulators, certification bodies or agents to take up a block of numbers and sell them on illegally.

But analysts question if the move will succeed in stopping the whitebox handset makers.

“I don't think this is helpful to restrain the whitebox handsets,” said Fang Meiqin, associate director at BDA, a telecoms consultancy, in Beijing.

“I think the more important step should be to restrain the handsets with the duplicative codes in the network, but this is often complicated and hard to do,” he said.