Article 18 – Acquisition of Portuguese citizenship – The following are the Portuguese citizens:

1. Those who are born in Portuguese territory, of Portuguese father, or of .Portuguese mother being illegitimate issues;
2. Those who are born in Portuguese territory of a foreigner father provided he his not in the service of his nation, unless they declare, by themselves being major or emancipated , or through their legal representatives ,, being minors that they do not want to be Portuguese;
3. The issues of Portuguese father, though expelled from Portuguese territory and illegitimate issues of Portuguese mother, born in a foreign country who come to establish domicile in Portuguese territory, or who declare by themselves, being majors or emancipated, or through their legal representatives, being minors, that they want to become Portuguese;
4. Those who are born in the Portuguese territory of unknown parents or of unknown nationality;
5. Those who are born in foreign territory, of Portuguese father, who resides there in the service of the Portuguese nation;
6. A foreign woman who gets married to a Portuguese citizen;
7. Foreigners who have been granted naturalization.
   § 1 – The declaration prescribed by the second clause shall be made before municipality of the respective residence; and that prescribed by the third clause shall be made before respective Portuguese consular agents or competent foreign authority.
   § 2 – The minor, upon attaining majority or being emancipated, may by way of new declaration object to the declaration which, during his minority, was made by his legal representative, in accordance with the second clause.
   § 3 – A Portuguese citizen who by any chance is deemed to be national of another country, as long as he resides in such country, is debarred from claiming the status of a Portuguese citizen.
   Section 1(4) particularly sub-clause (d) of the Goa Succession, Special Notaries and Inventory Proceeding Act, 2012 is a modification of this provision
   Article 19 – Requirements for grant of naturalization – The Government may grant a certificate of naturalization to the foreigners who so apply at the municipality of their residence, if found to satisfy the following conditions:
8. They are major or deemed as major, both by Portuguese law as well as by the law of their country;
9. They are able to earn a salary through their labour or have other means of subsistence;
10. They have resided at least for three years in Portuguese territory;
11. They are free from Penal liability;
12. They have fulfilled the law of military recruitment of their own country
    § 1 – The signature on the application referred to in this article requires to be authenticated .
    § 2 – The third condition is not essential to the descendants of Portuguese blood who have come to be domiciled in the country and may be dispensed with in case of a foreigner married to a Portuguese wife, and to one who has rendered or has been called to render any relevant service to the Nation which justifies the exemption.
    § 3 – The fourth condition is proved by a certificate of the country of the origin of the foreigner who applies for naturalization and by a certificate of his criminal record in Portugal.
    § 4 – Besides the documents mentioned above, only those which may be prescribed by treaty or convention between Portugal and the country of the person who applies for naturalization , may be demanded.
    § 5 – The documents are not subject to law of stamp duty and the Government may dispense them and substitute them by other information supplied by competent institutions, authorities and functionaries.
    Section 1(4) particularly sub-clause (d) of the Goa Succession , Special Notaries and Inventory Proceeding Act, 2012 is a modification of this provision
    Article 20 – Restrictions to the juridical capacity of the citizen by naturalization – The foreigner who has been granted naturalization shall not hold public office of any nature nor exercise functions of supervision or control of Companies or other entities dependent on the State through contract, or subsidized by it, till the expiry of at least ten years from the date of the grant of naturalization.
    § Sole paragraph – During the same period the foreigner who has been granted naturalization shall be subject to same restrictions which apply to the foreigners in respect of acquisition and holding of assets.
    Article 21 – Registration of certificate of naturalization – The certificates of naturalization shall have effect only when they are registered within the period of six months, from the date of the grant, in the records of municipality of the Taluka where the foreigner has established his domicile.