Technically, French immigration law and the Schengen Agreement require travelers to prove they have the means to leave the country, which is most easily demonstrated by a return or onward ticket. In 2026, with the full implementation of the ETIAS (European Travel Information and Authorization System), this requirement is more strictly enforced at the digital screening level. While a border officer may not ask every single traveler to show their ticket, having a "one-way" ticket often triggers a secondary inspection where you must prove you have sufficient financial means (typically €65–€120 per day) to purchase a ticket later and support yourself during your stay. If you are entering on a visa-exempt passport, the 90/180-day rule is paramount, and an onward ticket serves as your primary evidence of intent to comply with those limits. For those planning a flexible "backpacking" trip, many travelers utilize "refundable" tickets or travel insurance that covers "onward travel" to satisfy this requirement. Failure to provide proof of departure upon request can result in being denied boarding by the airline or being refused entry at the French border.