The distinction between the meaning of the terms citizenship and nationality is not always clear in the English language and differs by country.

[3] This difference does not exist in Finnish and both terms are translated as kansalaisuus when referring to national status.

Individuals born to unmarried Finnish mothers automatically receive citizenship without further requirements.

Children born within Finland to unmarried Finnish fathers acquire citizenship after paternity is established; those born abroad may receive that status automatically after their parents marry, or by declaration if their parents never marry.

[8] The minimum period is reduced to four years of continuous residence or six years of discontinuous residence for: spouses or registered civil partners of Finnish citizens who have been married for at least three years, registered refugees or stateless persons, children over the age of 15 applying with or after a naturalising parent,[10] and applicants with strong ties to the country who can also fulfill the language skills requirement early.

[11] Children under 15 with a naturalised parent may be granted citizenship immediately after becoming domiciled in Finland, provided that they meet all other requirements.

Conversely, individuals who acquire citizenship by declaration are entitled to gain that status after meeting the requirements.

[13] Finnish citizens may apply to relinquish their citizenship, provided that the applicants are ordinarily resident overseas and already possess another nationality or are in the process of naturalising in a foreign country.

Ordinary Finns can get Ålandic right of domicile after living on the islands for five years and proving their satisfactory knowledge of Swedish.

Ålanders lose their right of domicile after living outside Åland for five years, or on forfeiting their Finnish citizenship.

[21] A person who leaves the country to stay abroad for more than a year, loses municipal domicile immediately.

However, exceptions are made for persons who retain close ties to Finland or work as diplomats, missionaries or aid workers.

[22] Finnish and EEA member state citizens are domiciled in their places of residence immediately if they move into the country from abroad.

Other aliens are domiciled if they have a temporary residence permit for at least a year and the reasons for their stay point that they might remain in the country.

[28] Administratively, the municipal domicile is one of the most important factors in determining the jurisdiction of different state authorities over the person.

[30][31][32] In addition to the social and health services, the municipal domicile may yield other, somewhat less important rights relating to natural resources.

This means that not even a Finnish citizen moving into Finland is guaranteed the state social benefits immediately after entry, unless they can show that they intend to remain.

However, the Kela, which determines the domicile status, has a wide leeway to judge the circumstances of individuals.

[38] The changes to the law also mean that foreigners seeking naturalisation as a Finnish citizen do not need to renounce their former citizenship.

Given examples of such were terrorism, treason, hostage taking, people smuggling, inciting to war and espionage.

The law is not retroactive and therefore does not encompass people with Finnish citizenship who have joined the Islamic State of Iraq and the Levant.