a seat belt alarm system to alert users to the presence of an infant or child , or disabled , infirm or elderly person in a vehicle . the seat belt alarm utilizes a portable bracket configured to removably attach to a female receptacle of a seat belt system . the bracket includes a tension mechanism positioned to be acted upon by a male buckle of a seat belt system when the male buckle of the seat belt mates with the female receptacle of the seat belt system . in a depressed state , the tension mechanism activates a signal transmitter configured to transmit a local signal received by a signal receiver integrated in a keychain fob . when the keychain fob moves outside of a signal range while the tension mechanism remains in a depressed state , an alarm and / or red indicator light on the keychain fob is / are activated .