My x2b is telling me that my children's (age 13, 7) maintanence money will drop when he moves in with his partner (she has 2 boys, 14 and 17, the youngest is diabetic. Is this right??
That's correct, the CSA will deduct 20% from his income before calculating CM. So for example if he earns £1,000 net a month 20% is deducted (£200) leaving £800; CM for two children is then calculated at 20% of £800 = £160.