This dissertation explores the role of corporate finance in long-term investment planning in an organization, with a focus on the UK retail sector and a case study on Marks and Spencer. It discusses the concept and importance of corporate finance, the significance of long-term investments for business growth, and the use of multiple finance options for valuation. The study also evaluates investment appraisal techniques and their benefits for future company growth. The findings provide insights into the application of corporate finance in real-world situations and offer recommendations for investment planning.