Ans: There is actually no limit on how many outlets you can install on a GFCI board. Some premium options offer multiple USB ports on top of 2 to 4 standard outlets. But, you will have to make sure that you are using the GFCI wall outlet to power appliances that do not overload the unit. As you may already know, GFCI outlets have a specific capacity and overloading can certainly damage the outlet. For residential use, 2 outlets would be a safer choice.