Product Documentation

Phone Type Codes

Dec 22, 2015

The following is a list of phone type codes <TypeofPhone> returned by the TeleSign API, along with their descriptions.

Code Description Risk Level Recommended Action Detail
300 Undetermined Medium Flag

This is either an invalid phone number or a very new number. Because of its newness, TeleSign is not yet able to determine the phone type. This could potentially be a VOIP phone, so there is some risk involved with this type of phone number.

301 Fixed Line Low Allow

Fixed-line phones include traditional landline phones and VOIP phones that can be traced back to a particular address and cannot be obtained by a user outside the phone number’s designated country. Because these phone numbers are traceable, they are low-risk.

302 Mobile Medium-Low Allow

Mobile telephones are provided by companies such as Verizon, Cingular, or Sprint. Users of these phones must sign contracts, making these telephone numbers traceable. These phone numbers are generally low-risk. However, some prepaid mobile phones will be identified as Mobile.

Internationally, phones identified as mobile may also include TETRA mobile phones, cordless access systems, proprietary fixed radio access, and fixed cellular systems.

303 Pre-paid Mobile Medium-High Flag

These telephones can be purchased anonymously at many department stores. They work like other mobile phones, but their users are not contracted with a mobile phone company. Prepaid mobile phones generally cost between $30 and $100, making them unattractive for most fraudsters, but we still recommend flagging transactions made with this type of telephone due to a user’s anonymity. Also, not all prepaid mobile phones will be identified as prepaid; some will be identified as Mobile.

304 Toll-Free High Block

Toll-Free numbers are numbers starting with toll-free area codes, such as (800) numbers. Although sometimes used by legitimate users calling from companies, fraudsters can easily obtain toll-free numbers that either forward to their telephone which is located in another country or toll-free numbers that terminate at an Internet voicemail box. Toll-free numbers always forward to non-toll-free numbers. For this reason, any legitimate user who provides a toll-free number and is asked to provide a non-toll-free number will be able to do so. We therefore recommend blocking users of tollfree numbers.

305 Non-Fixed VoIP High Block

Voice Over Internet Protocol (VOIP) phone numbers are Internet-based telephone numbers. Non-fixed VOIP telephone numbers can easily be obtained by users who are not located in the country associated with the telephone number. They are untraceable and disposable; some can even be obtained for free. This means that a fraudster in Romania could easily obtain a US-based telephone number using a non-fixed VOIP service and receive a call to this number in his/her home in Romania.

306 Pager High Block

This phone number rings to a pager. Because pagers cannot receive verification calls, it’s best to block calls to these numbers. These calls are most likely requested by fraudsters who are inputting invalid phone numbers.

307 Payphone High Block

Calls to a payphone cannot be traced back to any one person; therefore, we recommend blocking verification calls to these numbers.

308 Invalid High Block

The telephone number entered is not a valid number or is a number originating on a Carribean island (i.e. Jamaica, St. Lucia, etc.)

309 Restricted Number High Block

The telephone number entered is a restricted number. In the US, restricted numbers include numbers that begin with 0 and numbers with the following area codes:

  • 900
  • 911
  • 411

Internationally, the following phone numbers are restricted:

  • Audiotext
  • Carrier selection
  • National rate
  • Premium rate
  • Shared cost
  • Satellite
  • Short Code
310 Personal Medium-Low Allow

A “Personal” phone number is a phone number which allows a Subscriber to receive calls at almost any telephone number, including a mobile number. The “Personal” number forwards to another phone number, which is determined by the subscriber. Because the “Personal” number can forward to either a landline or mobile number, it’s impossible to determine what type of phone the subscriber is using. However, because “Personal” phone numbers must be obtained from a phone company, there is little risk of fraud associated with this phone type.

311 Voicemail Medium-High Block

Voicemail phone numbers will ring directly to a user’s voicemail. Although this phone number was likely purchased through a phone company and may be traceable, it will be impossible to reach the user live at this phone number. In addition, any user providing a Voicemail number should also have a valid landline or mobile phone available. Therefore, we recommend blocking this type of phone.

320 Other Medium-High Block

Phone numbers labeled “Other” are all various types of phones that originate in non-US countries. The following types of phones may be included under the “Other” category:

  • Global title address
  • Inbound routing code
  • Videtext
  • VPN

Because clients should not be requesting calls to these phone types, we recommend blocking verification calls to these numbers. Any phone number entered that falls under the “Other” category was probably either entered incorrectly or was entered by a fraudster testing various phone numbers.