In recent years in Colombia, the informal resale of mobile telephone minutes as an alternative means of access to mobile telephony has allowed access for many low-income people not financially eligible for mobile plans. With data from a 2007 survey of low-income households in Colombia, we analyzed the main factors that determine the use of this kind of service. Using a probabilistic model (Logit), we found that people with a prepayment plan and those from smaller cities are more likely to use this alternative. Also, those subscribers in a plan with the leading carrier tend to use this service more often. © 2010 Elsevier Ltd.