Immigration
Dual citizenship rules by country: the 2026 quick reference
Which countries allow dual nationality, which require renunciation, and the three that create the most surprises.
Before you naturalise, check whether your home country will let you keep your original nationality. The answer is not always intuitive.
Generally permissive
Countries including the United Kingdom, United States, Canada and Australia permit dual citizenship without restriction.
Renunciation on naturalisation
Several countries — including Germany by default, Japan, Singapore and Austria — require you to renounce your prior nationality before naturalising, with limited exceptions.
The surprises
- A child born dual can sometimes keep both where an adult naturalising cannot.
- Some countries strip nationality automatically on naturalising elsewhere.
- Returning to a former nationality after renouncing is rarely straightforward.
Check the current rule for both countries before you apply for naturalisation. A dual nationality risk briefing is in the premium Vault.
This guide is general information, not legal or medical advice. Retain qualified counsel in the relevant jurisdiction before acting.