In the United States, the state governments have jurisdiction for issuing most professional licenses to individuals and corporations.
Fields that are regulated and licensed vary among individual states. Among regulated fields are health care professionals (medical doctors, nurses); psychologists; lawyers; teachers; engineers; social workers, occupational therapists, architects; tradesmen (plumbers, electricians), and certain service industry workers (bartenders; massage therapists; barbers).
It is now possible to verify an individual state license in all states online, via websites set up by each state government, by different agencies. Some private websites provide links to all such databases, in one location.
Licensing standards can differ widely from state to state. Also, the fields and occupations which states require to be licensed may differ widely. Some states may require a written examination for a license, while others may require several years of field experience as a student or intern. Some states have license requirements which are fairly uncommon among other states; for example, four states require licensing for interior designers. The State of Illinois requires four exams to become a "nail technician," or manicurist.