In order to keep your money in a safe place, you will need to buy a drop depository safe, in which the slot in the front, so it's called "front loading safe".
Step2
Place the safe in a location that the security camera can show when somebody approches the safe. You can place it on the top of a solid cabinet, or on the ground. If the safe is too heavy, just leave it on the ground.
Step3
Once your technicians or workers arrive and want to put the money in the safe, all they need to do is to drop the money in the slot. They have no access whatsoever to the combination or code of the safe.
Step4
At the end of the day, open the safe's door by inserting the code, once no one is around, and pull the money out of the safe.
Tips & Warnings
This article is based of experience of a well known company, with 12 technicians and workers, all with access to money (some of them are salesmen and some are working with the register).