Benefit fraud blocking child maintenance

[Mummaonherown]

Help!
Between July/October last year my ex claimed UC, he was awarded housing costs around 550 and single person allowance, he was laid off and found a new job on 17th October.

I opened a child maintenance case back in August 23 as he wasn't great at paying, I didn't have to use it, or should I say I let him off without paying a few times.
Anyway he went back to work in October (self employed, paid through CIS straight into bank account) and was paying me money every week until December 6th he told me due to Christmas/not working he can't afford to pay for his son and he would resume payments in January (he still got paid up until 23rd December just didn't give me a penny) I didn't argue I didn't see the point.
He kept delaying payments, told me I'd get money last Friday(17th) then said he didn't have it, so I called CSA.

They proceeded to tell me "because he's on benefits he only has to pay me £7.00 a week" I explained he wasn't on benefits anymore (he told me he had come off) but they told me he was lying and he's been paid on 1.11 1.12 and 1.11.
Obviously I was upset, he knows I've struggled especially over Christmas and he's been pocketing 900 extra he shouldn't have, whether he's using that money for his rent I don't know.

They said I had to report him to benefit fraud, so I did on Monday but I was told the investigation could take 6 months.
Child maintenance have said until they get notification from UC all he has to pay is the £7.00 a week, even though he clears £700.00 a week from his job, and worse still if found to be committing fraud by he will have to pay back money fraudulently claimed to the government by CSA will not backdate all the missed payments during this time and will reassess when the notification comes in, so technically my son loses out around £1700.

Surely there's something I can do, this doesn't sound right, my rent is going up in April and my son starts school.
I havent stopped contact I've always encouraged it (he has him 2 nights a month, his choice)
I work part time and life is expensive enough.
How should I take this further and AIBU to expect back dated payments.
I spoke to my ex on Tuesday and he's blamed me for "ruining him" for reporting him.
Anyone got any advice?

The whole system is awful. Before dealing with them I read all about how dreadful the CMS is but somehow because it's a government department (?) I thought they would have more powers! I sympathise op. My ex hasn't paid regular maintenance for over a year after quitting his PAYE job and going self employed. CMS say he doesn't have to pay because part of his income is from benefits. He has the children EOW otherwise I'd assume I would get £7 a week. The gut punch is that he waited until I bought him out of our house and he got £100k, before he stopped paying. My solicitor said that I was very generous and I could have offered less, but I wanted to be fair and give him the best opportunity to buy another property suitable for our children to stay. But at the time I had no idea that he would stop paying and if I had known I would have reduced my offer.

Anyway, he hasn't bought anywhere and I'm assuming he still has the majority of the money in the bank, which means he is committing benefit fraud because the savings limit is 16k. I can't bring myself to report him though.

I've had some success with asking him to pay half towards tangible things ie swimming lessons. I shouldn't have to ask of course and tbh I resent doing it greatly so I am thinking of not asking him anymore. The trouble is I am cutting my nose off to spite my face because I will be worse off. You may wish to consider doing this because you might find if he's presented with an invoice or for childcare it's not so easy to say no. CMS are so shite, these men have us over a barrel and they know it. As resident parents, if we claim UC, we are expected to work 30 hours a week (which I do and more) - I don't have a problem doing this because I need and want to support my family - but why is it that the same expectations aren't put on my ex? He's even started a masters degree with all his free time!

If you have proof that your ex is earning more money than he is claiming then I think the CMS do allow you to report it but you will need evidence. I am not sure exactly what is required - someone else might know.

Sorry I don't know if this was at all helpful to you but I promise there are others in the same boat.

@cadburyegg same here, I read about the failures of CSA and I didn't quite believe it, until I have had to deal with them.
He's working alright, works 5 days a week clearing 700 a week, paid straight into his bank account every Friday. He gets payslips as well (I've seen one, wasn't able to get the firms name) the evidence is there for the taking, it's just whether someone can be bothered to look into it.
He's seen my son's nursery costs, and while I do get a UC top up, he has said "the government pay for his nursery, so why do you need extra" which is not completely true, I don't get back the full 85% as shown, on average I get back 40% after all deductions are made from my wages and I only work part time as I cannot afford an extra day in nursery. He doesn't help at all, just the 2 nights a month and now he's got a new GF he hasn't bothered with his son, I'm at a loss.

I felt bad for reporting him, but I didn't feel that I had a choice, he's been pocketing close to 3500 every month since November and since 6th of December I haven't had a penny, he actually asked me to "borrow him" money 2 weeks ago!
But now I know CSA will not backdate the payments and chase for these payments to be made, I also feel that I'll be worse off in time.
My only solution to this is to look for full time work when my son starts school, it's just a worrying mess!