If you don’t sign up for the $100 plan and use the $10/day plan and use it more than ten days, you will be charged for however many days you use it. We are traveling for close to 20 days. Both my husband and I are on Verizon. I set up just one phone to be usable without Wi-Fi. Our total out of pocket will be $100 as long as we keep hubby’s phone on airplane mode. He will have access onboard with Wi-Fi. My phone has unlimited texts and data and 250 minutes of international calling.