This research study creates an inventory model for degrading products that considers the trade credit and also realistic market characteristics like advertising-motivated initial demand and unstable holding costs. The demand is characterized by a two-phase nonlinear ramp, where the sales initiate at a positive level because of advertising, grow over time until achieving a maximum, and subsequently stabilize throughout the product’s lifespan. To account for varying market conditions, three scenarios are examined: when the credit period is less than the demand peak, when it exceeds that point, and when it goes beyond the product’s total lifespan. Numerical cases are employed to evaluate the results of these situations and to define the issue as a nonlinear constrained optimization. The results that can assist companies in handling deteriorating goods stock more efficiently within trade credit agreements.