If you spend a lot of time traveling overseas, you’ll quickly realize that smartphones are not all smart. The rates for making and receiving calls are reminiscent of mobile phone plans in the 90s. If you don’t buy an expensive monthly international roaming plan, your phone calls may cost several dollars per minute. Even with those plans, calls and texts aren’t cheap, and the data you’re allowed is almost non-existent. If you use your phone overseas the way you use it at home, you’ll spend somewhere between $100-$150 per day. But there’s a way to avoid crazy fees. If you have an unlocked phone from AT&T, T-Mobile or Sprint, you can pop in a relatively cheap, local prepaid SIM card and keep your costs down. But that SIM card comes with a brand new phone number, which is a big deal if you need to receive calls on your real mobile number in real time. If you don’t, remember: you can always check your American smartphone voicemail a few times a day.