International Billed Number Screening Procedures for Collect and Third-Party Calling - Telephone Network and ISDN - Operation Numbering Routing and Mobile Service (Study Group 1) 8 pp
Recognized Operating Agencies (ROAs) are currently building, or planning to build, signalling interfaces for card validation as described by Recommendation E.113. These signalling interfaces could also be used to improve detection of attempts to charge telecommunication services to public telephones in place of, or as a supplement to, the payphone recognition tone described in Recommendation E.180. Use of these interfaces could also allow ROAs to offer optional billing features to customers who do not want collect or bill-to-third party calls charged to their accounts. Where the billed party has not expressly requested the call denial feature, the operator must ask the billed party to accept billing for the collect call or the call between the two other parties.