My sons Dad and I have a shared custody agreement. I have him 4x a week, he has him 3x a week...?

He applied for half of the child tax benefits, and was granted it last month. Does anyone know if this only applies to child tax? Should he be receiving the gst/hst portion as well? (Parents out there will know what I'm talking about, you get a larger amount of gst return depending on the number of children you have.)