More than 1.5 million foreign workers in Saudi Arabia have changed their residence status since April ahead of a planned crackdown on illegally registered expatriates in the world's leading oil exporter, the labour ministry said on Saturday.
Saudi Arabia is trying to reduce a black market in labour among the estimated nine million foreigners in the country, which the government says makes it harder for Saudi citizens to find jobs and economists say fosters inefficiency.
Unemployment among Saudis is officially estimated at 12 percent, but is seen as being higher among young people, something concerning to the authorities after joblessness contributed to Arab Spring protests in other countries.
Remittances from millions of workers in Saudi Arabia are important to the economies of countries including Yemen, the Philippines, Sri Lanka, India and Pakistan.
Huge crowds of foreign workers have queued for long periods in sweltering heat outside government offices and their own consulates in recent weeks, fearing fines and possible deportation if they fail to legalize their status before July 3.
More than 180,000 have also left the country, the passports authority said last week.
Registering foreigners properly has become important for the labour ministry after it imposed a new system of quotas last year that stipulate how many employees in particular types of position should be Saudi nationals.
Under Saudi law, foreigners must be sponsored by their employer and must work only in the field registered on their residence papers. In practice, many work for other companies and in different jobs.
Raids on companies earlier this year to inspect expatriates' documents prompted press reports of labour shortages as workers stayed at home to avoid being caught.
In April, King Abdullah announced a three-month grace period for foreigners to resolve their statuses, waiving fines and other fees for visa violations while expatriates changed their sponsorship to reflect their real work, or left the country.
The sudden announcement provoked massive queues outside government offices as millions rushed to address their status. In Jeddah, Indonesian workers rioted outside their consulate last week, angry over bureaucratic delays.