Identity Card Requirements

An identity card is the most basic, yet most heavily regulated document in daily life. Alongside a passport, it is the only document treated by the state as primary proof of identity — who you are, where you were born, where you live, and since when you legally exist in the records. This guide shows who must have it, what it must contain, and what obligations it carries.

At What Age Does It Become Mandatory

The age limit for mandatory possession of an ID card varies between countries, but in most, it ranges between 14 and 18 years. In some countries, an identity card is mandatory for all citizens regardless of gender or occupation, while in others it is voluntary — but in practice, it is required there for virtually every administrative step. Children can usually obtain an ID card even before reaching adulthood, at the request of a parent or guardian. This "minor" version usually has a shorter validity period — five years instead of ten — because a photograph quickly becomes outdated at an age when appearance changes from year to year.

What an Identity Card Must Contain

Although the design varies from country to country, the content is almost everywhere the same and based on international standards. An identity card legally must contain a minimum set of data that allows the unambiguous identification of a person.

• First and last name, in the official form from the vital records
• Date, place, and country of birth
• Nationality and gender
• A unique identification number or document serial number
• A photograph and often a signature
• Date of issue and date of expiration
• The authority that issued the document
• In newer cards — a biometric chip with a digital fingerprint, photograph, and electronic signature

Obligation of Carrying and Identification

Many countries have a legal obligation to carry an ID card in public spaces for adult citizens. In others, there is only an obligation to provide identification when requested by the police — a passport, driving license, or another photo document usually suffices instead of an ID card.

• Police control has the right to request identification — the obligation is to show the document, but not to hand it over without a legal basis
• For the purchase of certain goods (alcohol, tobacco, over-the-counter medicines in some countries), an ID card is requested as proof of age
• For services related to signing contracts, opening accounts, inheritance — an ID card or passport is mandatory
• Digital identity via a mobile application is replacing the physical carrying of the card in a growing number of countries for certain situations

What to Do When Data Changes

An identity card follows your legal data. When any of it changes — address, surname after marriage, nationality, or even surname after divorce — you are required to apply for a new ID card within the legal deadline. This deadline is often 15 to 60 days, and exceeding it is treated as an offense.

• Change of residence — a new ID card or a replacement address sticker, depending on the country
• Change of surname due to marriage, divorce, or an official change — a new card is mandatory
• Change of gender or name through an official procedure — a new card with new data
• Acquisition or loss of nationality — a new identification document

Identity Card as a Travel Document

In certain regions, an ID card is also used for crossing borders. Within the European Union and the Schengen Area, citizens can travel between member states using only an identity card. Similar bilateral agreements exist between other countries, particularly within economic and customs unions.

• To cross the border, it must be a biometric identity card — paper or old plastic ones are usually not accepted
• The validity period must cover the entire duration of the stay abroad
• For countries outside agreements, an ID card is not accepted even as a supporting travel document — only a passport
• Airlines may have stricter conditions than the border police, especially for tickets purchased through international reservation systems

Biometrics and Privacy Protection

Modern identity cards contain biometric data — a fingerprint, a digital photograph, and sometimes an iris scan. This data is protected more strictly than the rest of the card and is used only in communication with official authorities. Nevertheless, a physical card is a physical object that carries a lot of information on its own — and protecting that card in daily life is the responsibility of the holder.

• Do not leave photocopies of your ID card in unsecured online channels — email, social networks, groups
• Do not hand over the original for long-term safekeeping to third parties — neither to hotels nor to landlords
• Do not share a photograph of both sides of the card in full unless it is absolutely necessary for a specific service
• The biometric chip is protected, but everything written on the card in plain text — is there for anyone who sees it