Telephone numbers in Mongolia
976 is the international dialing country code for Mongolia. Numbering Convention
National significant numbers (NSN) are eight digits in length. There are two different domestic long-distance access codes in Mongolia: 01 (Mongolia Telecom network) and 02 (Mongolian Railway network). Dialing codes 
The following is a list of dialing codes for the different provinces of Mongolia. References

Mongolia
Telephone numbers