Child benefit: Couples will have to disclose incomes
28 April 2012 Last updated at 07:58 BST
New child benefit rules mean that some high earners and their partners will be expected to disclose their financial details to each other from next January.
People will also be able to find out from HM Revenue and Customs if their partners receive child benefit, or earn above £50,000 a year.
Experts say the changes will breach key tax confidentiality principles.
Ian Pollock reports.