if you don't spend it all, the money just stays in the childcare account, but as far as i know you can use it up until they are 16. This means that if you need holiday clubs and stuff when they've gone to school, you can still use it then. Personally i would get the full allowance of £243 each month if were you and start getting it now so you build up some credit. it's really easy to administarte (online). Just check that whoever you are planning to have childcare with accepts the vouchers. Some workplaces lock you in for the whole financial year and only allow changes in amounts at year end (mine will let you change it every month) If your wife also gets any when she's back at work, take care if you have another child as SMP is calculted on your pay, and as the vouchers come out before tax, it takes the overal pay amount that is taken ito account down