https://www.cnet.com/news/best-prepaid-wireless-plans-verizon-att-sprint-metropcs-boost-cricket-t-mobile/

Everyone needs a phone, but not everyone wants to sign anything resembling a carrier contract to get one. Maybe you'd rather pay only for the service you absolutely need while avoiding extra fees or maybe you just don't want to submit to a credit check.

Whatever your reason, a prepaid plan can be a brilliant option. When I lived in London for three years, I used a T-Mobile prepaid plan during the weeks when I returned home for visits. It let me keep my longtime US number and I wasn't paying for service I didn't use when I was in England. (My UK carrier, Three, gave me free data roaming in the US, but that came with its own set of complications.)