Meal Subsidy In Factory Canteen

I would like to write a simple program to enable worker to claim their meal allowance in the factory canteen. Basically they will have their access card to be touched at the card reader and your system can detect and deduct their monthly meal allowance credit. Each employee will be given a fixed amount of subsidy and the subsidy will vary every month as it follow the number of working days. In the end of every month , the canteen operator will print out a report to claim the subsidy from the factory owner.