Drawing from an ethnography with mixed-status families residing in Mexico, we examine what we term transborder literacies of (in)visibility, or diasporic people's innovative interactions around texts that prepare them to move across incompatible mononational institutions divided by borders. Through close attention to the literacy practices families engaged in as they applied for their children's U.S. passports from Mexico, we demonstrate how these literacies were not just about expanding authentic ways of reading and writing to include both U.S. and Mexican ways, but instead required unique transborder literacies across mutually unintelligible, racializing mononational systems so that children could (re)access their rights on both sides of the border. We argue that recognizing families' complex transborder literacy practices of (in)visibility could offer a novel anti-oppressive lens to transform how educators make sense of the complexity of immigrant families' literacies, movements, and educational supports across borders and national schooling systems.