Transports riboflavin and roseoflavin (PubMed:17541777, PubMed:22136195, PubMed:28406895). Can also transport FMN and FAD (PubMed:28406895). May confer roseoflavin resistance to S.davawensis, which naturally produces this antibiotic during stationary growth phase (PubMed:22136195). Introduction of ribM into a high performance B.subtilis riboflavin production strain may improve riboflavin production process. Belongs to the nicotinamide ribonucleoside (NR) uptake permease (TC 4.B.1) family.