I put both parents name and the child's name on the receipt. It is up to the parents to decide which parent claims it. It can make a big difference for some families to have one parent claim it instead of the other.

Unless they are divorced then I see no reason to not put both names on the receipt regardless of who actually writes the cheques.

Mine are along the lines of

XX amount received from 'jane doe' and 'john doe' for childcare for 'baby doe' for the period of 'start date' through 'end date'.
Then has my name and info.