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 temporary leaving 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.
With some countries, the validity of a visa is not the same as the 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 January 1 and March 30). Thus, the latest day the traveler could conceivably stay in the issuing country is July 1 (if the traveler entered on March 30). This interpretation of visas is common in the Americas.
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.
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 consider illegal immigration, even if the visa validity period is not 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 or visa exemption may result in detention not 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 deportable – 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 resident 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.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.