At least 1 million people in China have the same identity number as someone else but, according to the law, each number should be unique.

    "Identity duplications can cause a host of problems for citizens, as identity numbers are linked to their bank accounts, medical insurance, education certificates, crime records, and everything that matters in real life," an unnamed official from the Ministry of Public Security (MPS) said.

    Earlier this month, a Beijing resident was mistakenly arrested when he checked out at a net bar using his identity number, which happened to be identical to the number of a suspect pursued by local police.

    The MPS official explained that the errors occurred in the 1980s, when the coding of identity numbers was carried out entirely by hand.

    The official said the Ministry is striving to improve the situation by changing the identity number of people involved in such 'identity duplication' cases free of charge.

    "The Ministry encourages citizens who have the same identity number to negotiate between themselves, and decide which one of them will keep the original number and which one will get a new one. If the negotiation goes nowhere, we will rule that the person whose identity number was issued first keeps it," he said.

    Citizens who change their identity numbers have to change a series of other documents including bank accounts, medical insurance, education certificates, and so on.

    Identity numbers appear on the identity cards that are issued to Chinese citizens when they reach 16, and are supposed to be a citizen's "sole and inalterable permanent code", according to the Law of the People's Republic of China on Resident Identity Cards which came into effect in 2004.

    The 18-digit number includes 6 numerals representing the holder's birth place, 8 for date of birth, and another 4 for sex and differentiation.

    Most "identity duplication" cases occur with people who live in the same city and share the same birth place. But there are also cases that involve people from different provinces.

    Complaints have been heard around the country. Victims of "identity duplications" cannot apply for a driver's license, for instance, if someone with the same identity number has already beaten them to the gun.

    The MPS official said that years of efforts by the Ministry had greatly reduced the number of "identity duplications" involving people from the same city.

    "Our next step will be to eliminate the cross-city and cross-province duplications," he said.