As international migration has grown worldwide, the issue of how to assure the political rights of citizens living abroad has attracted much scholarly attention. One concern has been that if vote-buying is widespread in home countries, this practice could be exported to external elections. Although there have been numerous studies focused on electoral participation in external voting, there has been no systematic test of whether vote-buying is occurring across borders. This study aims to address this question by focusing on the 2018 federal elections in Mexico. Our list experiment shows that in our sample, approximately 32 per cent of Mexican immigrants in the United States experienced vote-buying during the electoral campaign. Furthermore, a multivariate analysis shows that the people most susceptible to vote-buying were living in areas where there was a high concentration of Mexican immigrants. The study results point to the importance of cross-border networks, which have been built between countries sending and receiving immigrants, in facilitating vote-buying across borders.