A subtle change in Canadian law has led millions of Americans to apply for Canadian dual citizenship after learning they can do so through ancestry.

Details on the new Canadian law for dual citizenship

Canadian Bill C-3 took effect Dec. 15, expanding eligibility for citizenship by descent. Previous rules limited citizenship to one generation, allowing Canadian parents to pass it only to their children. The new law now allows people born before Dec. 15 who have a Canadian grandparent, great-grandparent, or more distant ancestor to claim citizenship if they can prove the connection, according The Associated Press.

Those born on or after Dec. 15 must prove that their Canadian parent lived in Canada for more than 1,095 days.

Under the new law, descendants of Canadians are already considered citizens and only need to apply for a certificate of citizenship to finalize their status.

“You are Canadian, and you’re considered to be one your whole life,” immigration attorney Amandeep Hayer, who advocated for the law in the Parliament of Canada, said in a statement obtained by AP. “That’s really what you’re applying for, the recognition of a right you already have vested.”

He continued, “The best way I can put it is like, if a baby’s born tomorrow in Canada, the baby’s Canadian even though they don’t have the birth certificate,” he said.

Immigration lawyers nationwide have experienced a surge in cases and applications from Americans seeking dual Canadian citizenship. In Hayer’s practice in the Vancouver, British Columbia area, the number of cases has jumped from 200 per year to 20 consultations each day, per AP.

Why are Americans leaving?

In recent years, many Americans have considered moving out of the country due to politics and other factors. Michelle Cunha, of Bedford, Massachusetts, decided to uproot her life after decades in the U.S., believing it was the right move.

Meanwhile, Maureen Sullivan, of Naples, Florida, said she was motivated to move due to the immigration crackdown in Minnesota, calling the new bill a “little gift that fell in my lap,” she said, per AP.

For Troy Hicks, of Pahrump, Nevada, his decision was based on an international trip. He had a great-grandfather born in Canada, so having a “Canadian passport just seemed easier, better, more palatable.”

How much will Canadian citizenship cost?

The official application fee is just 75 Canadian dollars, roughly $55.However, costs could likely increase for those who require assistance from an attorney or genealogist to obtain the birth, death and marriage certificates necessary to verify their lineage, AP reported.

Some individuals have reported spending thousands of dollars, while others saved significantly by completing the forms themselves.

Interest in Canadian citizenship has surged since the law took effect, with Canada granting 1,480 people citizenship by descent between Dec. 15 and Jan. 31. More than 56,000 applications are now pending, and processing times average about 10 months, per AP.