The Validity of a Travel Visa Information
Visas can also be single-entry, which means the visa is cancelled as soon as the holder leaves the country; double-entry, or multiple-entry, which permits double or multiple entries into the country with the same visa. Countries may also issue re-entry permits that allow temporarily leaving the country without invalidating the visa. Even a business visa will normally not allow the holder to work in the host country without an additional work permit.
Once issued, a visa will typically have to be used within a certain period of time.
The Validity of a Visa
With some countries, the validity of a visa is not the same as the authorized period of stay. The visa validity then indicates the time period when entry is permitted into the country. For example, if a visa has been issued to begin on January 1 and to expire on March 30, and the typical authorized period of stay in a country is 90 days, then the 90-day authorized stay starts on the day the passenger enters the country (entrance has to be between 1 January and 30 March). Thus, the latest day the traveller could conceivably stay in the issuing country is 1 July (if the traveller entered on 30 March). This interpretation of visas is common in the Americas.
Interpretation of Visa
With other countries, a person may not stay beyond the period of validity of their visa, which is usually set within the period of validity of their passport. The visa may also limit the total number of days the visitor may spend in the applicable territory within the period of validity. This interpretation of visa periods is common in Europe.
Validity Period of a Visa
Once in the country, the validity period of a visa or authorized stay can often be extended for a fee at the discretion of immigration authorities. Overstaying a period of authorized stay given by the immigration officers is considered illegal immigration even if the visa validity period isn't over (i.e., for multiple entry visas) and a form of being "out of status" and the offender may be fined, prosecuted, deported, or even blacklisted from entering the country again.
Entering a Country Without a Valid Visa
Entering a country without a valid visa or visa exemption may result in detention and removal (deportation or exclusion) from the country. Undertaking activities that are not authorized by the status of entry (for example, working while possessing a non-worker tourist status) can result in the individual being deemed liable for deportation—commonly referred to as an illegal alien. Such violation is not a violation of a visa, despite the common misuse of the phrase, but a violation of status; hence the term "out of status".
Even having a visa does not guarantee entry to the host country. The border crossing authorities make the final determination to allow entry, and may even cancel a visa at the border if the alien cannot demonstrate to their satisfaction that they will abide by the status their visa grants them.
Some countries that do not require visas for short stays may require a long-stay visa for those who intend to apply for a residence permit. For example, the EU does not require a visa of citizens of many countries for stays under 90 days, but its member states require a long-stay visa of such citizens for longer stays.