The Federal Communications Commission announced Wednesday that U.S. wireless carriers are on track to meet voluntary commitments they made one year ago to provide alerts that help customers avoid unexpectedly high bills.

Under a voluntary agreement announced by FCC Chairman Julius Genachowski in October 2011, members of CTIA-The Wireless Association agreed to provide free, automatic alerts to wireless customers who are approaching or exceeding their data, voice, or text limits, or who are about to incur international roaming charges not covered by their service plans. Participating companies account for about 97 percent of U.S. wireless customers. The agreement came after the FCC in 2010 proposed rules designed to protect customers from “bill shock.” In announcing the voluntary agreement, Genachowski cited a 2011 Consumers Union survey, which found that about 20 percent of U.S. wireless customers had incurred unexpected charges in the previous year.

Yesterday was the deadline for participating companies to provide at least two categories of alerts, and FCC staff reported at yesterday’s FCC open meeting that all companies had met the deadline. Participating companies will have to provide all four categories of alerts by April 2013. A page on the FCC’s website tracks carriers’ progress and provides links to further details on each carrier’s website.