Where an American Can Hold Two Passports at Once

There’s a moment most expats remember — standing at a government counter in Dublin or Lisbon or Mexico City, holding a passport that isn’t navy blue, quietly wondering whether Washington is about to send a letter. It isn’t. Dual citizenship has been legal for Americans since a 1967 Supreme Court ruling, and millions of US citizens now carry a second passport. The interesting question isn’t whether you’re allowed. It’s which country is genuinely worth the years of paperwork, the fees, and — for a few of them — the tax complications that follow you for life.

• Dual citizenship has been permitted for Americans since Afroyim v. Rusk (1967). Naturalizing abroad does not, by itself, strip your US citizenship.
• Ancestry routes — Ireland, Italy, Portugal, Germany, Israel — are the fastest second passports for most Americans.
• Residency routes (Canada, Mexico, Australia, New Zealand) take longer but don’t depend on your grandparents.
• Spain offers a two-year fast track to certain nationalities, but its renunciation rule is a genuine grey area.
• Wherever you move, the IRS follows. The US taxes citizens on worldwide income regardless of where they live.

First, Clear Up the Myth That Scares People Off

Plenty of Americans still believe that taking a foreign oath automatically cancels their US citizenship. It doesn’t. Under the 1967 ruling in Afroyim v. Rusk, the government can’t take your citizenship away without your voluntary consent. Yes, the oath you swear when naturalizing somewhere else includes the phrase “I absolutely and entirely renounce and abjure all allegiance” to any foreign state — but Washington reads that as a formality toward your old country, not a resignation letter to the United States.

For citizenship to actually be lost, the State Department looks for a voluntary act done with the specific intent to relinquish. Obtaining a second passport isn’t enough. Running for office in another country isn’t enough. Even serving in a foreign military usually isn’t, unless you’re a commissioned officer in a hostile force. And practically speaking, most people never come close to that line. You file your US taxes, you renew your US passport, you vote — and you hold two documents in the same drawer.

How These Countries Were Actually Judged

Passport rankings get all the attention, but they’re the least useful metric here. A Maltese passport is lovely; you’re not getting one. What matters is whether a normal American with a job, a mortgage and limited patience can realistically qualify.

So I weighed six things: does the country allow dual nationality, how fast can an American realistically qualify, is there an ancestry route, what does it cost in fees and years, how strong is the passport you end up with, and — the one nobody mentions on Instagram — what it does to your tax life.

The Honest Shortlist

Ireland — The Cleanest Ancestry Route on Earth

If you have a grandparent born in Ireland, you can register on the Foreign Births Register without ever setting foot in the country. No residency, no language test, no interview, no tax treaty gymnastics. The fee is a few hundred euros and the wait is roughly nine to twelve months. What you get is an EU passport and the right to live and work anywhere in the union. If your parent was born in Ireland, you’re already a citizen — you just need the paperwork. It’s the single best-value move on this list.

Italy — Powerful, But the Door Just Narrowed

Italy’s jure sanguinis path built an entire industry of genealogists and consulate-appointment brokers. In March 2025, a new decree limited descent claims to people with a parent or grandparent born in Italy, closing the great-grandparent route for most applicants. Lines that pass through a woman who gave birth before 1948 still need an Italian court case. It’s slower and messier than it used to be, but an Italian passport is a full EU passport with no residency requirement attached.

Portugal — The Slow Burn With the Best Payoff

Portugal allows citizenship through a grandparent, and its naturalization clock has been among the shortest in Europe — historically five years of legal residence. A 2025 nationality reform was set to stretch that timeline, possibly to seven or ten years, so anyone building a plan around Portugal should verify the current rules before moving. The Sephardic route that drew thousands of applicants a few years ago is effectively closed. Still, Portugal remains one of the friendliest countries in Europe for Americans who want to stay long-term.

Germany — The Rules Changed Dramatically in 2024

Until recently, Germany forced new citizens to give up their old nationality. Since June 2024, multiple nationality is permitted, which reshuffled the whole ranking. Standard naturalization now arrives after five years of residence, or three with strong integration. Separately, descendants of people persecuted by the Nazi regime can claim citizenship under restitution law without ever living in Germany. If your family history runs through that door, it’s worth a lawyer’s hour.

Canada — The Least Dramatic Option

Three years of physical presence in the last five as a permanent resident, then citizenship, then two passports. Canada permits dual nationality without fuss. The trade-off is straightforward: you actually have to live there, and Canada taxes residents on worldwide income, which stacks on top of your US filing obligation. The foreign tax credit usually smooths it out, but budget for an accountant who understands both systems.

Mexico — Closest, Cheapest, Quietly Underrated

Mexico has allowed dual nationality since 1998. Naturalization generally takes five years of residency, dropped to two for people married to a Mexican citizen, with Mexican children, or who are nationals by birth of a Latin American or Iberian country. It’s a short flight from the US, the cost of living is manageable, and the passport opens doors across Latin America. For Americans who want a second nationality without upending their lives, this is often the most practical answer.

Spain — Fast Track, One Big Asterisk

Spain’s general residency requirement is ten years, but nationals by origin of Ibero-American countries, Andorra, the Philippines, Equatorial Guinea and Portugal qualify in just two. Spain also asks new citizens to renounce their previous nationality — except for those same exempt countries. Here’s the wrinkle: a renunciation made before a Spanish civil registrar doesn’t dissolve your US citizenship, because the US only recognizes a formal renunciation made to a US consular officer abroad. People do end up holding both, but it’s legally murky enough that you should never navigate it without a bilingual attorney.

Israel, Australia and New Zealand — Solid, If Slower

Israel grants citizenship to Jewish applicants under the Law of Return essentially on arrival, and permits dual nationality. Australia wants four years of lawful residence including one as a permanent resident; New Zealand wants five years with a strict presence test. Both allow dual citizenship and both are genuinely excellent passports. Neither is fast.

The Comparison, Side by Side

The Tax That Follows You Anywhere

This is the part that turns a romantic idea into a spreadsheet. The United States taxes its citizens on worldwide income no matter where they sleep at night. Claiming the Foreign Earned Income Exclusion — around $130,000 for 2025 — or the Foreign Tax Credit usually knocks your US bill down to near zero if you’re paying taxes abroad. But the paperwork doesn’t disappear: foreign bank accounts totaling more than $10,000 at any point in the year must be reported on an FBAR, and larger holdings trigger Form 8938 under FATCA.

Stack a second passport on top and nothing changes. You still file. You still report. The only thing that changes is that you now have an exit door if you ever want it.