To ask for the bill in Italian, you can say:

• "Il conto, per favore."
  (The bill, please.)

Other polite variations include:

• "Potrei avere il conto, per favore?"
  (Could I have the bill, please?)

• "Mi porta il conto, per favore?"
  (Could you bring me the bill, please?)

These phrases are commonly used in restaurants or cafes when you want to pay.