This discussion addresses the possibility of claiming a refund for the 2017-18 financial year, even if the standard time limit has passed, particularly concerning inverted duty structures. While the general consensus is that the time limit has expired, it's suggested that a refund might still be possible by challenging a rejection before the Commissioner (Appeals) if strong grounds exist. Filing the refund claim is recommended for safety, and it may also be a prerequisite for claiming refunds for subsequent years like 2018-19 and 2019-20.