This assignment examines the application of taxation law in a case study involving Big Bank Ltd. The focus is on their attempt to claim input tax credit for advertising expenses incurred under the GST Act 1999. The analysis utilizes relevant legal provisions, rulings (GSTR 2006/3), and case law (Ronpibon Tin NL v. FC of T) to determine the legitimacy of Big Bank's claim. The assignment also explores the implications of paragraphs 11-5, 15-5, and subsection 15-25 within the context of input tax credit eligibility.