Visa requirements for Comorian citizens

Many countries require a minimum number of blank pages to be available in the passport being presented, typically one or two pages.[286] Endorsement pages, which often appear after the visa pages, are not counted as being available.

An International Certificate of Vaccination or Prophylaxis is required to prove that someone has been vaccinated against yellow fever

Many African countries, including Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Republic of the Congo, Côte d'Ivoire, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Liberia, Mali, Mauritania, Niger, Rwanda, São Tomé and Príncipe, Senegal, Sierra Leone, South Sudan, Uganda, and Zambia, require all incoming passengers to have a current International Certificate of Vaccination or Prophylaxis, as does the South American territory of French Guiana.[287]

Some other countries require vaccination only if the passenger is coming from an infected area or has visited one recently.[288]

In the absence of specific bilateral agreements, countries requiring passports to be valid for at least 6 more months on arrival include Afghanistan, Algeria, Anguilla, Bahrain,[289] Bhutan, Botswana, British Virgin Islands, Brunei, Cambodia, Cameroon, Cape Verde, Cayman Islands, Central African Republic, Chad, Comoros, Costa Rica, Côte d'Ivoire, Curaçao, Ecuador, Egypt, El Salvador, Equatorial Guinea, Fiji, Gabon, Guinea Bissau, Guyana, Haiti, Indonesia, Iran, Iraq, Israel,[290] Jordan, Kenya, Kiribati, Kuwait, Laos, Madagascar, Malaysia, Marshall Islands, Mongolia, Myanmar, Namibia, Nepal, Nicaragua, Nigeria, Oman, Palau, Papua New Guinea, Philippines, Qatar, Rwanda, Samoa, Saudi Arabia, Singapore, Solomon Islands, Somalia, Sri Lanka, Sudan, Suriname, Tanzania, Thailand, Timor-Leste, Tokelau, Tonga, Turkey, Tuvalu, Uganda, United Arab Emirates, Vanuatu, Venezuela, and Vietnam.[291]

Countries requiring passports valid for at least 4 months on arrival include Micronesia and Zambia.

Countries requiring passports valid for at least 3 months on arrival include Albania, Honduras, North Macedonia, Panama, and Senegal.

Countries requiring passports with a validity of at least 3 months beyond the date of intended departure include Azerbaijan, Bosnia and Herzegovina, Montenegro, Nauru, Moldova, and New Zealand. Similarly, the EEA countries of Iceland, Liechtenstein, Norway, all European Union countries (except the Republic of Ireland) together with Switzerland and the United Kingdom also require 3 months validity beyond the date of the bearer's intended departure unless the bearer is an EEA or Swiss national.

Bermuda requires passports to be valid for at least 45 days upon entry.

Countries that require a passport validity of at least one month beyond the date of intended departure include Eritrea, Hong Kong, Lebanon, Macau, the Maldives[292] and South Africa.

Other countries require either a passport valid on arrival or a passport valid throughout the period of the intended stay. Some countries have bilateral agreements with other countries to shorten the period of passport validity required for each other's citizens[293][294] or even accept passports that have already expired (but not been cancelled).[295]

Some countries, including Australia, Canada, Fiji, New Zealand and the United States,[296] routinely deny entry to non-citizens who have a criminal record.

The government of a country can declare a diplomat persona non grata, banning their entry into that country. In non-diplomatic use, the authorities of a country may also declare a foreigner persona non grata permanently or temporarily, usually because of unlawful activity.[297]

Israeli border control Entry Permit (issued as a stand-alone document rather than a stamp affixed in a passport)

Kuwait,[298] Lebanon,[299] Libya,[300] Sudan,[301] Syria,[302] and Yemen[303] do not allow entry to people with passport stamps from Israel or whose passports have either a used or an unused Israeli visa, or where there is evidence of previous travel to Israel such as entry or exit stamps from neighbouring border posts in transit countries such as Jordan and Egypt.

To circumvent this Arab League boycott of Israel, the Israeli immigration services have now mostly ceased to stamp foreign nationals' passports on either entry to or exit from Israel (unless the entry is for some work-related purposes). Since 15 January 2013, Israel no longer stamps foreign passports at Ben Gurion Airport. Passports are still (as of 22 June 2017) stamped at Erez when passing into and out of Gaza.

The Saudi Commission for Tourism and National Heritage claims that having an Israeli stamp does not disqualify someone from visiting Saudi Arabia.[304]

Iran refuses admission to holders of passports containing an Israeli visa or stamp that is less than 12 months old.

Entry Permit to Nagorno-Karabakh issued in Yerevan as a stand-alone document rather than a visa affixed in a passport

Due to a state of war existing between Armenia and Azerbaijan, the government of Azerbaijan not only bars entry of Armenian citizens, but also all citizens and nationals of any other country who are of Armenian descent, into the Republic of Azerbaijan.[305][306]

Azerbaijan also strictly bans any visit by foreign citizens to the separatist region of Nagorno-Karabakh[307] (the de facto independent Republic of Artsakh), its surrounding territories, and the Azerbaijani exclaves of Karki, Yuxarı Əskipara, Barxudarlı, and Sofulu which are de jure part of Azerbaijan but under the control of Armenia, without the prior consent of the government of Azerbaijan. Foreign citizens who enter these territories will be permanently banned from entering the Republic of Azerbaijan[308] and will be included in their "list of personae non gratae".[309] As of 2 September 2019, the list mentioned 852 people.

Upon request, the authorities of the largely unrecognised Republic of Artsakh may attach their visa and/or stamps to a separate piece of paper in order to avoid detection of travel to their territory.

A fingerprint scanner at Dulles International Airport collects biometric data on visitors, which can be used for confirming identities.

Several countries mandate that all travellers, or all foreign travellers, be fingerprinted on arrival and will refuse admission to or even arrest travellers who refuse to comply. In some countries, such as the United States, this may apply even to transit passengers who merely wish to quickly change planes rather than go landside.[310]

Fingerprinting countries include Afghanistan,[311][312] Argentina,[313] Brunei, Cambodia,[314] China,[315] Ethiopia,[316] Ghana, Guinea,[317] India, Japan,[318][319] Kenya (both fingerprints and a photo are taken),[320] Malaysia upon entry and departure,[321] Paraguay, Saudi Arabia,[322] Singapore, South Korea,[323] Taiwan, Thailand,[324] Uganda[325] and the United States.

Many countries also require a photo be taken of people entering the country. The United States, which does not fully implement exit control formalities at its land frontiers (although long mandated by its legislature),[326] [327] [328] intends to implement facial recognition for passengers departing from international airports to identify people who overstay their visa.[329]

Together with fingerprint and face recognition, iris scanning is one of three biometric identification technologies internationally standardised since 2006 by the International Civil Aviation Organization (ICAO) for use in e-passports[330] and the United Arab Emirates conducts iris scanning on visitors who need to apply for a visa.[331][332]