Childcare element of working tax credits

[B1984]

I have dd who starts reception this september and ds who starts nursery next january.We really need extra money so i am planning to work at least 16 hours a week to qualify for childcare vouchers.Does anyone know if i can put my ds to nursery every day until 3.00(that way i can pick up dd from school).ds will be 3 so we would have couple of hours free and the difference we would pay ourselves and then claim back,i think.
does anyone know if this would work,if not correct me please?!thanks

bump

It's not a case of paying childcare then claiming it back.

You can only claim up to 80% of childcare expenses and not many people get that much back. It will depend on what you are earning (and remember if you claim as a couple it is both of your earnings that they take into account, so you may even be over the threshold for WTC and not entitled to help with childcare at all.)

Have a look here and you can use the calculator to work out what you might get