Bluetooth transmitters function in all countries across the world. Bluetooth technology differs from other radio technologies in that it only transmits information within a small range. As a result, Bluetooth transmitters do not ordinarily depend on compatibility with other radio technologies used in any given country.
Restrictions relating to where and how Bluetooth transmitters can be used vary by country. The official Bluetooth fast facts list states that the technology operates in the ISM, or industrial, scientific and medical, band, which is largely unregulated. Restrictions tend to be based in law and confined to specific usage scenarios, rather than being technological in nature.
For example, hands-free devices are banned for use during driving in most US states, according to Wired. However, there are also extreme cases where repressive regimes may attempt to ban the technology outright. North Korean authorities allegedly restrict and confiscate smartphones that use Bluetooth technology.