In this paper, a novel nitrogen-containing carboxyl-functionalized organophosphorus compound was exploited for enhancing the flame retardant properties of cotton fabrics. In particular, 1,2,3,4-butanetetracarboxylic acid and sodium hypophosphite were used as environmentally-friendly binder and catalyst, respectively. Besides, to avoid the formation of insoluble calcium salt during home laundering, the treated samples were recoated employing three sol-gel solutions. Treated and untreated samples were thoroughly characterized to understand the bonding between coatings and substrate, as well as their thermal and fire behaviour. The results obtained from flame and combustion tests revealed that the treated fabrics were able to control the combustion process.