Telephone Number Identification Phone-type Codes

Code Phone Type Risk Level Recommended Action Description
0 Undetermined Medium Flag MaxMind is not 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.
1 Fixed Line Low Allow Fixed-line phones include traditional land-line phones and VoIP phones that can be traced back to a particular address and cannot be obtained by a user in another country. Because these phone numbers are traceable, they are low-risk.
2 Mobile Low-Medium 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.
3 PrePaid 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 $60 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.
4 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 toll-free numbers.
5 Non-Fixed VoIP High Block Voice over Internet Protocol (VoIP) phone numbers are Internet-based telephone numbers. US-based, non-fixed VoIP telephone numbers can easily be obtained by users in other countries. 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.
6 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.
7 Payphone High Block Calls to a payphone cannot be traced back to any one person; therefore, we recommend blocking verification calls to these numbers.
8 Invalid Number High Block The telephone number entered is not a valid number.
9 Restricted Number High Block The telephone number entered is a restricted number. Restricted numbers include numbers that begin with 0 and numbers with the following area codes: 900, 911, 411.
10 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.
11 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.
20 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
  • Videotext
  • 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.