There's no single right answer. It depends on how much you sell, how many SKUs you have, and how much variance you can tolerate. A small shop with 50 products might do a full count monthly. A busier one might do it weekly or even daily for fast-moving items.

A practical approach: do a full count when you notice things are off (wrong numbers, unexplained shortages) or at least once a quarter. In between, do spot checks on your top 20% of products by value or by movement. If those match the system, you're in good shape. If not, dig in before the gap grows.

Use your inventory app to record counts and adjust. The goal is to correct drift before it becomes a big problem. Less drama, more accuracy.