A location without a guard at 6 in the morning is not an HR problem. It is a furious client calling, a penalty clause being activated, and, depending on the contract, a termination on the table. In private security, attendance control is not an administrative formality: it is the difference between fulfilling the service or losing it. Here I explain how to control guard attendance when you have twenty locations spread across the city, 12-hour shifts, and reliefs that cannot fail, what Argentine regulations require, and why paper timesheets are no longer enough.