Unfortunately, the problem is that a divorce decree in and of itself is not considered a written declaration per IRS regulations. Even if there is a divorce decree in place that states the parent by whom the child can be claimed, it's not enough. Internal Revenue Code 152(e)(2) requires Form 8332 or other sufficient written declaration to be attached to the noncustodial parent's tax return because the IRS is not involved in personal court cases unless it is a criminal issue. The form is an instrument. If a custodial parent violates the agreement, the noncustodial parent must go to the state court for a remedy, not the IRS. Since many people make the mistake of assuming that the IRS will rely on a divorce decree, this is the reason why it's suggested that the form be attached.
@Bdog2020
