The Birthright citizenship (Jus soli), is the right of any children born in the territory of a state to a citizenship. Today more than 30 countries offer birth citizenship to babies.
Almost all states in Europe, Asia, Africa and Oceania grant citizenship at birth based upon the principle of right of blood, in which citizenship is inherited through parents rather than birthplace, or a restricted version of jus soli in which citizenship by birthplace is automatic only for the children of certain immigrants. The popularity of this form of citizenship gave rise to birth tourism.
Birth tourism is the practice of traveling to another jus soli country for the purpose of giving birth to receive automatic citizenship for the new born child. In an effort to discourage birth tourism, several countries have modified their citizenship laws at different times, mostly by granting citizenship by birth only if at least one parent is a citizen of the country or a legal permanent resident who has lived in the country for several years.
Lex soli is a national law used in practice to regulate who and under what circumstances an individual can assert the right of jus soli.
The unconditional automatic birthright citizenship is more prevalent in the Americas, Caribbean while restricted version is offered in some european countries and in australia.  No European country presently grants unconditional birthright citizenship. Malta has abolished birthright citizenship
Let us take a look on the birthright citizenship offered by Golden visa and Citizenship by investment (CBI) countries. All the CBI/Golden visa countries offer provision for dual citizenship along with birthright citizenship.
1. United States
Automatic
The 14th Amendment to the United States Constitution, ratified in 1868, provides: All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside
According to a Migration Policy Institute analysis
- 1.3 million children live with two parents who are both unauthorized
- 1.8 million live with one unauthorized parent and one parent who is a legal immigrant
- 909,000 live with only one parent, who is unauthorized
The United States taxes its citizens and green card holders worldwide, even if they have never lived in the country.  U.S. permanent residents are also subject to worldwide taxation. Worldwide taxation is often cited as a reason for U.S. citizens or permanent residents to relinquish their citizenship or residency status
2. Canada
Automatic
Citizenship by birth in Canada leads to automatic unconditional citizenship regardless of the immigration status of parents, unless they are diplomats.
3. Australia
Restricted
Persons born in Australia acquires Australian citizenship by birth only if at least one parent was an Australian citizen or permanent resident; or else after living the first ten years of their life in Australia, regardless of their parent’s citizenship status
4. Ireland
Restricted
Ireland amended law in 2005Â to require that at least one of the parents be an Irish citizen; a British citizen; a resident with a permanent right to reside in Ireland or in Northern Ireland; or a legal resident residing three of the last four years in the country (excluding students and asylum seekers)
Ireland was the last country in Europe to abolish automatic jus soli.
5. United Kingdom
Restricted
Since 1 January 1983, at least one parent must be a British citizen or be legally “settled” in the country with permanent status or upon the 10th birthday of the child regardless of their parent’s citizenship status
6. Malta
Abolished
Malta no longer offers jus soli or birthright citizenship
Malta offered birthright citizenship for those anyone born in Malta before 1 August 2001, regardless of their parents circumstances, were offered automatic Maltese citizenship.
7. Portugal
Restricted
A child born in Portuguese territory to who does not possess another nationality is a Portuguese citizen. Also, a person born to foreign parents who were not serving their respective States at the time of birth is a Portuguese citizen if the person declares that they want to be Portuguese and provided that one of the parents has legally resided in Portugal for at least two years at the time of birth
8. Spain
Restricted
A child born in Spain to foreign parents may acquire Spanish citizenship jus soli if either one of the parents was also born in Spain or neither of the parents can transmit their nationality to the child (stateless parents).
9. Greece
Restricted
Greek Nationality Code of 2004 states that “A person born in Greek territory acquires by birth the Greek nationality if not acquiring alien nationality or is of unknown nationality”.
The 2015 amendment of 2004 Cod (Law 4332 of 2015, G.G. A/76/9 July 2015), a child born in Greece by foreign parents, shall acquire the right of Greek nationality with a combination of preliminary school attendance and parents’ legal residence in Greece (5 years, 10 if the child is born prior to 5 years of legal residence).
One year after the implementation of the law (as from July 2016), 6,029 children had been granted Greek nationality, out of 27,720 submitted applications
10. New Zealand
Restricted
Since 1 January 2006, a person born in New Zealand acquires New Zealand citizenship by birth only if at least one parent was a New Zealand citizen or permanent resident (includes Australian citizens and Permanent Residents)
11. Antigua and Barbuda
Automatic
Guaranteed by the Constitution to Person is born in A&B.
Unless the child is born to a foreign diplomat and neither parent is a citizen, or one of the parents is an enemy alien and the child is born in a place then under occupation by the enemy.
12. Dominica
Automatic
Person is born in Dominica. Unless born to a foreign diplomat and neither parent is a citizen, or one of the parents is an enemy alien and the child is born in a place then under occupation by the enemy.
13. Grenada
Automatic
Person is born in Grenada. Unless born to a foreign diplomat and neither parent is a citizen, or one of the parents is an enemy alien and the child is born in a place then under occupation by the enemy.
14. St Lucia
Automatic
Person is born in St Lucia. Unless born to a father who is a foreign diplomat and neither parent is a citizen, or the father is an enemy alien and the child is born in a place then under occupation by the enemy.
15. St Kitts and Nevis
Automatic
Person is born in St Kitts. Unless born to a foreign diplomat and neither parent is a citizen, or one of the parents is an enemy alien and child is born in a place then under occupation by the enemy.
