This article needs additional citations for verification .(July 2022) |
A mobile dial code (MDC) is a grouping of 3 to 10 numbers following either a "#", "##", or "*" "**" used to create a short, easy-to-remember phone number. Historically, MDCs were used for repair-related purposes by landline and wireless carriers. More recently, MDCs have been made available for commercial use. MDCs are dialed just like a regular telephone number. Businesses can send automatic responses upon contact, such as by text message.
MDCs are used by wireless carriers for the following purposes:
For an MDC to be used as a vanity telephone number, all major wireless carriers must provision it to their users. Suppose the business needs to use the MDC in more than one State. In that case, accommodations can be made for one MDC to be shared by multiple users on a state-by-state, or even local area by local area basis, through advanced routing technology, called geo-routing. Inbound calls to MDCs can either be automatically routed based on the caller's area code or by asking the caller to type out or speak their zip code into the phone.
MDCs may be easier to remember than full phone numbers and thus easier to brand. Therefore, they may be helpful in lead generation businesses that generate and then sell leads to potential businesses or other companies.
USSD (Unstructured Supplementary Service Data) codes [1] are mobile dial codes that can be used for communicating with the service provider's computers (i.e. for WAP browsing, prepaid callback service, mobile-money services, location-based content services, menu-based information services, and as part of configuring the phone on the network).
Abbreviated dialing codes [2] involve a similar technology that supports only voice calls.
A 2D bar code [3] involves using a graphic that must be photographed or scanned by a mobile phone camera before presenting the caller with a response.
![]() | This section needs expansionwith: other countries. You can help by adding to it. (March 2025) |
In the United States, each wireless network controls how its MDCs will be used. As such, when wireless customers call an MDC, their call is routed to the end user that their carrier selects.