Telephone numbers consist of ten digits; a 3-digit Area Code, a 3-digit Office Code and a 4-digit Station Code. Those "Code" names will be used within this Knowledge Base.
901 was the original Area Code assigned in 1947 to the state of Tennessee. Soon households wanted their own unique telephone number rather than share "party-lines" with neighbors, so in 1954 Area Code 901 stayed in West Tennessee and Area Code 615 was assigned to Middle and East Tennessee. Forty-seven years later, pager and mobile phone usage had grown to the point that in 2001 Area Code 901 stayed in Shelby County and a few surrounding counties in Southwest Tennessee, and the remainder of West Tennessee was assigned Area Code 731.
Central Office Codes, also known as "Exchanges" or "Prefixes", are assigned to Telephone Companies. In Weakly County, Citizens Communications, parent company of Frontier Communications, is the Incumbent Local Exchange Carrier. In the Martin area, Frontier retained the Office Codes 587 and 588 after the 2001 731 Area Code transition, then in 2004 added the 881 Office Code at the request of UTM as our expansion grew. Frontier has also been assigned Office Codes for other towns in Weakley County, all these are considered "Local" by Frontier and can be called from other Frontier numbers within the county simply by dialing their 7-digit Office and Station codes, without using the 731 Area Code. Frontier also has agreements with cellular companies doing business in Weakley County to consider their cellular Office Codes as "Local", so these cellular numbers can also be called from Frontier numbers using just the 7-digits.
Frontier routes all inbound calls beginning with 731-881 exclusively to UTM Telephone Services. UTM Telephone Services then has the responsibility of assignment of the 4-digit Station Code, including reporting its location to E911 Emergency Services.