Bill could ban US citizens from holding dual citizenship

US citizens in Switzerland could soon be banned from holding dual citizenship due to a bill proposed to the United States’ Senate.

US citizens in Switzerland could face dual citizenship ban

Republican Senator for Ohio Bernie Moreno has introduced the “Exclusive Citizenship Act of 2025” to the US Senate. If the bill were to pass, US citizens would no longer be able to hold dual citizenship.

The new act would affect both dual citizens living in the US and those living abroad. For example, US citizens living in Switzerland would be forced to give up their US passport if they were to obtain Swiss citizenship, and residents who already hold US and Swiss passports would be forced to renounce one passport.

According to the bill’s general outline, it would ensure that “An individual may not be a citizen or national of the United States while simultaneously possessing any foreign citizenship”. It states that, if and when the act is adopted, “A citizen of the United States who [...] voluntarily acquires foreign citizenship shall be deemed to have relinquished United States citizenship”.

Those with dual citizenship will have one year to either renounce their US or foreign citizenship, and dual citizens who do not comply by the deadline “shall be deemed to have voluntarily relinquished United States citizenship”.

Under the act, the US Secretary of State and Department of Homeland Security would also keep a record of those who had renounced their US citizenship, who would then be "treated as an alien for purposes of the immigration laws".

The son of Colombia’s former health secretary, Moreno arrived in the US at age five and became a US citizen at 18, eventually renouncing his Colombian passport. The former car dealership CEO previously supported a pathway to dual citizenship for US migrants, but has since U-turned.

“Being an American citizen is an honor and a privilege,” Moreno said when announcing the bill, “and if you want to be an American, it’s all or nothing. It’s time to end dual citizenship for good.”

What does this mean for US citizens in Switzerland?

For now, it is unclear how much support Moreno’s bill will gather and whether it is legally solid. To become law, it would first need to pass a vote in the US Senate. If politicians choose to advance the bill, it is likely to face legal challenges at the next stage.

The US Supreme Court has previously affirmed that formal renunciation is the only way a US citizen can lose their citizenship. The affirmation is based on the 1952 Kawakita vs. United States case, in which a dual US-Japanese national was convicted of treason against the US during the Second World War.

If passed, the US State Department and Department of Homeland Security would also have to organise a system to log and process all US dual citizens, a further logistical hurdle. Official estimates of the number of US citizens who hold another passport vary widely, from 500.000 to 5,7 million.

According to the Federal Statistical Office (FSO), around 32.000 US citizens live in Switzerland, of whom almost 16.000 are dual US and Swiss nationals.

This article was originally published on IamExpat in Germany.