The measure, first announced earlier this year, enables eligible migrants to apply for a one-year residence and work authorization if they can prove they arrived in Spain before January 1 and have lived in the country for at least five months.

Applicants must also demonstrate a clean criminal record, according to the government.Migration Minister Elma Saiz said applications will open online this week and in person from April 20, with a deadline of June 30. Submissions can be made across a network of 60 social security offices, 371 post offices and five immigration centers nationwide.

Sánchez described the policy as both “an act of justice and a necessity,” emphasizing that migrants already contributing to Spain’s economy should be allowed to do so under regulated conditions, including paying taxes. “We recognize rights, but we also demand obligations,” he said in a social media statement.

The government estimates that around 500,000 undocumented migrants could qualify, though independent analysts suggest the number may be higher. Spanish think tank Funcas has estimated that approximately 840,000 migrants are currently living in the country without legal status.

Spain, a nation of about 50 million people, has seen rapid demographic changes in recent years, with roughly 10 million residents born abroad. Many migrants originate from Latin America and North Africa, drawn by employment opportunities or fleeing economic hardship and instability.

Undocumented workers are heavily represented in key sectors such as agriculture, tourism and services, areas that have underpinned Spain’s recent economic expansion. Officials argue that regularizing their status will strengthen tax revenues, improve labor protections and support the sustainability of the welfare system.

The policy marks a departure from broader European trends, where governments have largely focused on tightening immigration controls and increasing deportations.

It also contrasts with the stricter immigration stance adopted by the administration of Donald Trump.However, questions remain over the government’s capacity to process a high volume of applications within the limited timeframe. A union representing immigration officers warned that existing administrative resources may be insufficient to handle the expected surge.

Opposition leader Alberto Núñez Feijóo criticized the measure as unsustainable, despite his party having overseen similar large-scale regularizations in the early 2000s.The government enacted the measure through a decree amending immigration law, bypassing parliament where it lacks a majority and where a previous attempt at reform had stalled.

Spain has carried out multiple migrant amnesties in the past, including six between 1986 and 2005 under governments of differing political alignments.