Immigration office or Questura is at Via della Fortezza, Florence.
How long does the process of PdiS?
The length of the process of PdiS seems to be varied, some can get it in 4 weeks, some in 2 months, most people get it in 1 year or more. When you are submitting your application, ask the officer, how long will it take to process your PdiS. He/she will say you may come back in 2 weeks, but don’t be surprised because often when you go back after 2 weeks, your file will probably remain untouched or simply stacked on his shelf.
The key is to be patient, keep smiling, and speak/ask the officer politely. Keep asking when can you have your PdiS ready? Ask for a certain date and timing.