After you file


@Sheina315 wrote:

What if my ex husband amended his return electronically? 


If his original tax return has already been filed and accepted by the IRS claiming the child, then you cannot e-file your tax return.  You can only print and mail your tax return claiming the child on your return, it cannot be e-filed since the IRS already has the SS number of the child on an Accepted tax return.  Amending a tax return does not change the IRS database for Accepted tax returns.  Since an amendment has been filed you can file your tax return at any time.