The chief executive of HM Revenue and Customs has warned parents to not leave registering for child benefits "until the last minute", on the eve of the stated deadline.
Lin Homer told BBC Radio 5 Live:
We think there are about 200,000 people who need to get off their backsides and do something.
HMRC is committed to helping people pay the right amount of tax and urges parents who have been affected by the changes to child benefit to register for self-assessment.
We know that lots of people leave it until the last minute.
More top news
The PM promises to double to 200,000 the number of homes built under an existing scheme aimed at easing Britain's housing shortage.
The Met Office has weather warnings in place for snow and ice until 10am in the north and west.
The plan, which would effectively strip banks of the benefit of recent corporation tax cuts, forms part of the party's election manifesto.