New York City prohibits students from carrying cellphones in public schools, but many are reluctant to leave their phones behind. As a result, the rule has created a modest side business for shops near some schools that allow students to store their phones for a fee.

But along one commercial stretch in Queens that is close to a cluster of schools, storing cellphones has become almost a matter of economic survival. Not only do the merchants reap a small but welcome source of income, but they have also come to rely on the ancillary sales of food and drinks they make to the students dropping off their phones in the morning and picking them up in the afternoon.

“It helps me keep my business going,” said Ali Ahmed, 59, the longtime owner of a candy store near the intersection of Hillside Avenue and Parsons Boulevard, where waves of teenagers flow through on weekdays, headed to and from one of several nearby schools, including Hillcrest and Jamaica High Schools.

The phone storage business has transformed the storefront economy around the bustling intersection, producing such a strong business incentive that local owners say they must take part in order to avoid losing foot traffic.