Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first.
Is this spouse or child maintenance?
How much does he earn?
Does he have any other income at all?
How old is your son?
No forces pension?
I have to ask - do you believe he is being honest about his earnings?
Was there actually a final financial order made within the divorce proceedings?
The problem that you face is that if his earnings are what you think they are his maintenance liability will be just 12% of his gross income - considerable less than he is paying now.
If you believe that he does not earn much then you may as well accept what he is paying you as and when.
However if there is any chance that he is earning more then you should apply to the CMS (old CSA) to do an assessment
Please ask if you need further details - and i am sorry that another expert accepted the telephone request.
Sadly you will get less if he is being honest - but I am far from certain that he has told you the truth at all
No you can deal with the matter yourself although in fact there is no need to ocntact them at all - just go straight to the CMS