Rollback provision in Advance Pricing Agreements permits retrospective arm's length determination subject to specified procedural conditions. Amendments add a rollback provision to APA rules allowing an APA to determine or specify the method for ascertaining arm's length price for the same international transaction in specified prior years, subject to conditions including timely filing of returns and transfer pricing reports, a dedicated rollback application with payment of an additional fee, withdrawal of related appeals, prohibition where appellate disposal has occurred or where rollback would reduce declared income or increase loss, and procedural steps for filing modified returns and informing relevant authorities.