This is based on a change agreed by politicians in the summer, saying the aim is to find people who may pose a threat to national security.
In June, the government agreed with the centre-right opposition parties to introduce "automatic checks" on everybody who applies for a residency permit here.
In the past, such checks have only taken place when a person applies for citizenship. When it comes to asylum seekers, the intelligence and security service would only be notified if the Migration Agency found something in their investigation that would indicate that a person may be a security threat. Last year, for example, this happened in about 700 cases.
But since July this year, the Migration Agency has passed on information about all those who apply for residency permits in Sweden to Säpo. So far, over 20,000 such cases have been forwarded. Oskar Ekblad is the head of special operations at the Migration Agency.
"We see an opportunity here to increase the work to find threats against the national security, in that all people who apply to Sweden are actually checked by the security service," he says.
He adds that this includes also those who have applied for family reunion, a work permit or a student visa and who have handed in their application at a Swedish embassy around the world - not just those that the Migration Agency meet in Sweden for an interview about their asylum application.
The information forwarded to Säpo is what Ekblad calls "the type of information that enables the security service to identify people, like names" and other information that he is not able to disclose.
If a person is deemed to pose a threat against national security, Säpo can, after an investigation, recommend that the Migration Agency does not grant a residency permit. Last year, that happened in 50 cases.
"Sweden, like any other country, is exposed to risks following migration. These risks should not be exaggerated, most people who come here have of course nothing to hide, but just like the security checks at an airport, this is something that should be part of the process when you apply for residency permit," says Oskar Ekblad.
Security services asylum seeker investigations grow1:29 min 1:29 min
Migration Agency reports more potential security threats6:32 min 6:32 min