Authored by Scherezade Maestre and Áine Hickey, this article was originally published by Global Mobility Lawyer on December 8, 2025. Original publication can be accessed here.
Business travel used to start at the airport. Now it begins with a lengthy online questionnaire that politely asks: “Are you absolutely sure you’re not a security risk?”. Welcome to the world of increasing pre-travel authorizations and digitized checks.
Recent years have brought us a clear trend of digitization, modernization of border management systems, and ‘upgrades’ to border security systems. With the aim of gathering relevant information on travelers to ensure any security concerns are identified before they enter, electronic pre-travel authorizations require visa-exempt nationals to obtain approval before travelling to their destination country.
The United Kingdom has recently joined other long-standing champions of pre-travel authorizations with the phased introduction of its Electronic Travel Authorisation (ETA). In doing so, it has aligned itself with countries such as the United States, which uses ESTA (Electronic System for Travel Authorization), and Canada, which has its own eTA. This year has also seen the European Union introduce a digitized Entry/Exit System (EES) setting the stage for the upcoming European Travel Information and Authorisation System (ETIAS), a pre-travel authorization system for visa-exempt nationals scheduled for late 2026.
For most travelers, these systems are straightforward. The authorities have set up clear exemptions for holders of work permits, study permits, diplomatic passports and the usual suspects. However, dual nationals may end up getting caught in the administrative maze and being refused boarding on planes to their own countries if the correct documentation is not provided. This article explores these challenges, examines what dual nationals can expect, and provides practical guidance for navigating them.
The concept of dual nationality means that a person is a national of two or more countries at the same time. In practical terms for the purposes of business travel, it may mean that they have two (or more) passports.
What is often unknown to travelers is that many countries have rules for dual nationals that require them to enter on a specific passport. How do these work? How can dual nationals manage pre-travel authorizations, and what should they avoid doing?
United States of America and ESTA
For dual nationals holding both U.S. citizenship and the citizenship of a foreign country, the rules are clear: U.S. nationals are required by law to enter and leave the United States on their U.S. passport. In contrast, an ESTA application is for citizens of countries within the Visa Waiver Program only. Because the ESTA application asks applicants about their nationality, including whether they have or have ever had citizenship in other countries, U.S. nationals will simply not be eligible for an ESTA.
It is important to note that U.S. nationals need a valid U.S. passport to enter, and can do so right up until it expires. If the U.S. passport is expired, a new passport will need to be obtained before any travel to the U.S. Good news is: the U.S. does offer emergency passports under particular circumstances!
United Kingdom and the ETA
For British dual nationals, understanding and navigating entry rules can be more complex. While there is no absolute legal requirement for British nationals to travel to the United Kingdom on their British passport, trying to travel on a foreign passport can pose particular challenges.
In theory, where a passenger presents a non-British passport and claims to be British, but does not hold any evidence of their citizenship (generally, a valid passport or a certificate of entitlement), the border officer will conduct all relevant checks to satisfy themselves that the passenger is British. In the past, this meant that it was generally possible for British dual nationals to travel to the UK on their foreign visa-exempt passport, such as their EU passport, and then proving this to the border officer to enter as a UK national.
However, since the introduction of the ETA, the risk is transferred to the transport operator, who may deny boarding if the person cannot provide satisfactory evidence of their eligibility to enter the UK under their right of abode; a logical response given that transport operators can be fined for bringing inadequately documented passengers to the UK. It is relevant to mention that expired British passports, photocopies of British passports, or British naturalization certificates do not count as acceptable proof.
Dual British nationals are ineligible for ETA, eVisa or immigration permission under their other nationality. The transitional approach to the ETA has meant that so far the issues have been far and few, but an increase is expected with ETA enforcement in 2026.
To facilitate travel, British nationals may wish to apply for a second passport, provided they meet certain criteria. Alternatively, British nationals abroad might be able to apply for an emergency travel document.
Dual nationals travelling to the Schengen Area and Cyprus
The ETIAS system will cover all Schengen countries, as well as Cyprus (which does not yet benefit from border-free crossings but is in the process of fully joining the Schengen Area). All these countries share a common set of visa rules which apply to short stays (up to 90 days in any 180-day period) and for transit through international transit areas of airports in the Schengen area.
Once someone has crossed the external Schengen border and border guards have verified that the documents satisfy the entry requirements, this person will not be subject to further checks when travelling within the Schengen area (unless internal border controls are temporarily reinstated).
Thanks to the freedom of movement, nationals of any ETIAS-requiring countries (as well as Ireland) are able to enter and travel throughout the Schengen area with either a valid passport or a national identity card that is, at the very least, valid on the day of travel/entry into the country. The European Commission has clearly stated that dual nationals who are citizens of any of these countries are exempt from ETIAS regardless of any other nationality they may hold and must always travel with their EU/EEA/CH documents.
Once again, the only legally authorized entry is with valid documents issued by the EU/EEA/CH country of nationality. In this case, it is even more important, as entry to the entire Schengen area should be made using this passport. Even if the traveler is not entering their country of nationality, they should not use their other passport. This applies even without ETIAS in place; otherwise, they could be inadvertently using their Schengen allowance under their other nationality and risk overstaying.
The three main pre-travel authorizations we have explored require travelers to enter using the passport of their nationality; failure to do so can lead to difficulties and, in some cases, is illegal. There are limited workarounds, which is why immigration professionals consistently advise entering each country with a national passport. Doing so helps avoid data errors, being treated as a tourist in your own country, or even being mistakenly considered an overstayer.
In practice, even when a traveler holds the correct travel document, complications can still arise with airlines, many of which do not allow different passports to be used for separate segments of a journey. If a single passport is linked to all segments, online check-in can fail, and presenting a different passport at the gate may cause boarding delays—or worse. Given the increasing complexities of modern travel, the passport a traveler uses has never been more important in ensuring a smooth journey!
Scherezade Maestre
Director, Vialto Partners
UK Solicitor & Spanish Lawyer
Áine Hickey
Manager, Vialto Partners
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