You need more than a SSN. If you are the non-custodial parent you also need a 8332 form signed by the custodial parent that releases the dependent to you. For divorce decrees after 2009 the IRS no longer accepts divorce decrees - they only accept a signed 8332 form. The 8332 form must be attached to your tax return of mailed within 3 days with a 8453, (U.S. Individual Income Tax Transmittal) if e-filing.
Your remedy is the court that made the order to hold your ex spouse in contempt if the ex refused to supply the necessary items in order to comply with the court order.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
