Late fees in invoicing are an important aspect of business transactions, as they can help ensure timely payments and maintain a healthy cash flow. However, it is crucial for businesses to understand when late fees are applicable and how they should be implemented in order to avoid any legal or ethical issues. In this article, we will explore the various factors that determine when late fees are applicable, discuss the calculation methods for late fees, and highlight the importance of clear communication with clients regarding these fees. We will also examine the impact of late fees on business relationships, including both potential risks and benefits.