HappyWithLife, sorry just saw your Q. WTC for me is 80 something quid a week with 1 child working 30+ hrs, I'm not sure what IS is but I think it's at £65? or around that. Plus my (very small) earnings as well, which housing benefit take into account but which are too little to affect tax credits. Even so, I still work out slighter better off than I would be on IS. My rent is quite a lot higher than HB pays, so I have to make up the difference myself. I would struggle on IS and probably have to move.
Of course, the new gov are proposing an end to that kind of situation, with their new white paper. Gits. So don't rush into self employment, because it looks like it might soon be a lot more tricky to be SE while looking after a child. See this thread:
From which the following quote comes..
"Will self employed low earners be unable to get universal credit? The White Paper says that they will no longer get away with declaring very low earnings, but will be deemed to be earning the minimum wage for the declared hours worked. If they declare few hours, they will be subject to the same conditionality as those on JSA (as will employed low earners).No more cottage industries for those of us who aren't employable or don't have childcare. It's litterpicking in a flourescent jacket in front of the neighbours, or starvation. Part time work or starting your own business won't save you. I was feeling quite happy about the future and then this...it seems like there isn't any future now for those of us on benefits or tax credits."
Might be worth watching and waiting, I don't know. I feel very insecure since I read the thread above.