I don't know of any prepaid plans that don't require you occasionally top-up your balance in order to keep the line active. Why is that? In response to “A cell phone for (almost) nothing,” Mark points out, “As far as I can tell, each of these prepaid plans has an expiration date. That is, if you buy 100 minutes but don’t use them in 90 days, they’re gone. This never made sense to me. You’re paying in advance for a service. Why should it expire when they have your money? Do you know of any prepaid SIM cards with no expiration term?”This is a very good point. I don’t know of any prepaid plans that don’t require you occasionally top-up your balance in order to keep the line active. Why is that? I asked Virgin Mobile.“We do this because of the cost of maintaining accounts that are no longer active,” explains Corinne Nosal, a spokesperson for Virgin Mobile. “Our research tells us that people who have no activity on their account for over 90 days are no longer using the phone. Other companies have this same requirement.” She points out Virgin Mobile customers also have the option of buying service by the minute: You can pay $6.99 a month and 10 cents a minute. The $6.99 a month fulfills the top-up requirement. Or you can pay $90 and have a year to use the money in the account. “If toward the end of the first year, you still have $45 in your account, for example,” she explains, “top-up with $90 and the $45 will roll forward. You now have a balance of $135 in your account against minutes for the second year.” OK, some of those options do address the inconvenience of having to remember quarterly to top-up a phone you use only as an emergency car phone. And $90 a year for a mobile phone seems a fair price. But I think Mark was making the point that the money spent should not expire. “I’m not picking on cell phone carriers,” he adds. “Prepaid calling cards and gift cards that expire are equally bad. If an account is inactive for a year, then I’d agree — those phone numbers ought to be recycled. But if I want an emergency phone, and I don’t have an emergency, and I want to keep it active by making a short call once every 364 days, then I ought to be able to do just that, without ‘topping it off’ if my balance isn’t zero.” I agree. Why not allow customers to simply place the occasional call to customer service (or to order pizza) to keep the phone number live? I suspect that cell phone carriers would find an untapped market if they explored this. I, for example, would have bought a phone for my car “just in case”—even though I already have a cell phone—but I don’t want to add “Top-up emergency phone” to my to-do list. “And if one of them found a market niche by doing what I’m proposing,” says Mark, “the others would certainly follow suit.” Technology Industry