I remembered last year more than 3 months statements not excepted. My husband brought the form to the school, my electricity bill expired by a few days (can't remembered). The school asked him to come again.
And one more thing, if the wife signed the form, but your husband bring the form to school. The wife need to write an authorisation letter, stating that the wife (ID no.) authorised her husband (ID no.) to hand in the form for the child.
So please be careful, make sure you don't hand in the form on last day.