アマゾンカスタマー 3 This SIM card is data "only." The words "data only" are not mentioned in the advertisement. The word "data" does appear in the advertisement in small print in the top right corner ("Japan prepaid data SIM") but to the neophyte, it is not obvious that this means "data only." Any time I purchased a prepaid SIM card elsewhere in the world, it came with a phone number. As far as I know, the majority of people who buy a prepaid SIM card expect the SIM card to have a temporary phone number. That is usually the point of a prepaid SIM card.