This happened in April and I assumed it was some kind of end-of-tax-year-adjustment. Reduced from £312 pm to approx £220. I have two dc, both at school and the Child Tax Credit payment hasn't altered.
I have been paid again today and it's still almost £100 less than usual.
As far as I'm aware, nothing in my circs has changed and I will definitely phone them tomorrow but it's bugging me now!
Anyone else had this happen or know why it might be?