Substitutes to IMR are widely available to consumers on travel in these economies. The
availability of such alternative technologies, the use of which can be more cost-effective than
IMR, could prompt providers to bring down their retail prices. Eleven economies39 cited
international calling cards as the most widely-available substitute technology to mobile roaming.
Other common alternatives included: Voice-over-Internet protocol (VoIP) (10 economies); local
pre-paid SIM cards (10 economies); and international phone numbers (6 economies). Additional
substitutes might include single-card-multiple-number (SCMN) service, international call
forwarding service, and call back service. However, these alternatives do bear some
disadvantages not found with roaming. Examples might include use of a different mobile number
than used domestically; loss of coverage; decreased call quality; and loss of access to contacts.