Every now or then, QB users might stumble upon various types of errors, one such error is QuickBooks Point of sale error 176109. This error code is related to invalid product code or number code and usually occurs when trying to open or register QuickBooks Desktop Point of Sale. If you have stumbled upon any such error, then this article can be really helpful to you. This article is entirely based on the causes and the easiest ways to tackle the QuickBooks Error code 176109: Invalid Product Code or Invalid Product Number.