Parental Kidnapping Prevention Act (PKPA) and the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA) may apply to your termination of parental rights cause of action if an order for visitation and/or custody was entered in another state.
You are only required to file a termination of parental rights cause of action if anyone who is required to consent to the adoption and relinquish her rights pursuant to Section 63-9-310 of the South Carolina Code of Laws, as amended, has not done so; this is deemed to be a contested case.
Basic rule is if an order for custody or visitation from another state has been entered and is determined to have been entered by a state that had jurisdiction to issue the initial child custody decree and it maintains exclusive, continuing jurisdiction then both PKPA and UCCJEA apply to the termination of parental rights cause of action.
If the adoption is uncontested and all required parties have signed consents and relinquishments, we have no need for a termination of parental rights cause of action and neither PKPA nor UCCJEA apply.
If either PKPA or UCCJEA or both apply, the termination of parental rights cause of action may need to be made in the state that has entered a child custody/visitation order and maintains continuing, exclusive jurisdiction.
Short Anaylsis: No order from other state or uncontested action with order from other state; no PKPA or UCCJEA. Order from other state and contested action; PKPA and UCCJEA apply.
I have linked to a recent case from the South Carolina Court of Appeals for an analysis of PKPA and UCCJEA in termination of parental rights cases here.