Interest relief measures for delayed GST returns reduce rates and conditionally waive late fees if returns filed within specified periods. Sets out phased interest relief and conditional late fee waiver for delayed GST returns: for larger taxpayers an initial nil interest window followed by a reduced interest period before resumption of the normal rate; for smaller taxpayers an extended nil interest window and subsequent reduced interest period before normal rates apply; late fee waiver applies only if returns are filed within dates specified in the notifications, otherwise late fee accrues from the original due date until filing.