Year 381 (CCCLXXXI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Syagrius and Eucherius (or, less frequently, year 1134 Ab urbe condita). The denomination 381 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Regulation of the telephone numbers in Serbia is under the responsibility of the Regulatory Agency of Electronic Communication and Mail Services (RATEL), independent from the government. The country calling code of Serbia is +381. The country has an open telephone numbering plan, with most numbers consisting of a 2- or 3-digit calling code and a 6-7 digits of customer number.