Revocation of release of claim to an exemption. For tax years beginning after July 2, 2008 (the 2009 calendar year for most taxpayers), new rules apply to allow the custodial parent to revoke a release of claim to exemption that was previously released to the noncustodial parent on Form 8332, Release/Revocation of Release of Claim to Exemption for Child by Custodial Parent, or similar form. The revocation is effective no earlier than the tax year beginning in the calendar year following the calendar year in which the custodial parent provides, or makes reasonable efforts to provide, the noncustodial parent with written notice of the revocation. Therefore, if the custodial parent provides notice of revocation to the noncustodial parent in 2009, the earliest tax year the revocation can be effective is the tax year beginning in 2010. You can use Part III of Form 8332 for this purpose. You must attach a copy of the revocation to your return for each tax year you claim the child as a dependent as a result of the revocation.