The Henley Passport Index is a global ranking of countries according to the travel freedom allowed by those countries' ordinary passports for their citizens.^[3] It started in 2006 as Henley & Partners Visa Restrictions Index^[4] and was changed and renamed in January 2018.^[5]

The index annually ranks 199 passports of the world by the number of countries that their holders can travel to without requiring a visa.^[6] The number of countries that a specific passport can access becomes its visa-free "score". In collaboration with the International Air Transport Association (IATA),^[7] and using official data from their global database, Henley & Partners has analysed the visa regulations of almost all the world's countries and territories since 2006.^[4][8]

The Henley Passport index ranks passports according to the number of destinations that can be reached using a particular country's ordinary passport without the need of a prior visa ("visa-free").^[9][10] The survey ranks 199 passports against 227 destination^[11] countries, territories, and micro-states.^[12][13][14]

The IATA maintains a database of travel information worldwide and all destinations that are in the IATA database are considered by the index.^[15] However, because not all territories issue passports, there are far fewer passports ranked than destinations about which queries are made.^[16]

To determine the score for each country or territory,^[17] its passport is checked against the IATA database in several steps:

1. Each of the 199 passports on the list is checked against all 227 possible travel destinations for which travel restriction information exists in the IATA database. The score is updated throughout the year.^[18]
2. Each query must satisfy certain conditions:
   • passport is issued in the country of nationality
   • passport holder is an adult citizen of the country that issued the passport and a lone traveller, not part of a tourist group
   • entry is sought for tourism or business
   • the stay is a minimum of three days
3. Further conditions:
   • queries are made only for holders of normal passports, not diplomatic, service, emergency, or temporary passports; and other travel documents are disregarded
   • passport holders need not meet any complex requirements for entry (for example, possessing a government-issued letter, translations, or empty pages)
   • passport holders have all necessary vaccinations and certificates
   • passport holders are arriving at and departing from the same airport
   • passport holders are seeking a short stay rather than a transit
   • the port of entry is a major city or capital, in cases where this is required
   • requirements by the destination country or territory regarding a particular length of validity of passports are disregarded
   • passport holders meet all basic requirements for entry (for example, holding a hotel reservation or having proof of sufficient funds or return tickets)
   • advance passenger information and advance approval to board are not considered to be a visa requirement or travel restriction, neither is the requirement to pay airport tax
4. If no visa is required for passport holders from a particular country or territory to enter the destination, then that passport scores 1. The passport also scores 1 if a visa on arrival, a visitor's permit, or an electronic travel authority (ETA) can be obtained because they do not require pre-departure government approval, perhaps because of specific visa-waiver programs in place.
5. Where visas are needed, or where passport holders must get government-approved electronic visas (e-Visas) before departure, a score of 0 is given. If passport holders must get government approval before leaving in order to obtain a visa on arrival, this also scores 0.
6. The score for each passport is then totalled by adding up its scores for all destinations.^[19]
7. The index ignores temporary restrictions or airspace closures.^[20]
8. It considers mobility data based on national GDPs and the percentage of global wealth that the country's passport could provide access to.^[21]