Mouth agape, pit-in-your-stomach: You’ve just opened your cell phone bill and had “bill shock!” Unexpected  charges can really run that bill up if you exceed plan limits for voice, data, texting and dreaded roaming charges.

A study by the Federal Communications Commission (FCC) found that one in six Americans with cell phone plans have had bill shock. Of those, 20 percent had overage charges of $100 or more. Yikes! Here are five ways you can combat cell phone bill shock:

  1. Track Your Usage: Weekly or bi-weekly, monitor your voice, data, and text usage on your cell phone. The method depends on your carrier and phone model. Some require an online account with your carrier. Other methods include checking the designated settings on your phone or using short codes you dial from your cell. Try setting a recurring reminder in your digital calendar.
  2. Download the Pageonce Application: If you have an iPhone or Blackberry, download the free Pageonce Cell Phone Tracker application on your phone. This handy application will you alert you when you're within 20 percent of your minutes, text messages, and data limits. It will also send an alert when you're within 5 percent of your usage limits and one more alert when you exceed limits. Click here to get the free Pageonce application.
  3. Negotiate Overages with Your Carrier: If you receive an unexpected bill with overage charges, call your carrier's customer service department and try to negotiate an exception or discount. It never hurts to ask (politely)!
  4. Switch to a Pre-Paid Plan: If you have a hard time monitoring your usage levels or find your self frequently hitting or exceeding your plan limits, you may want to consider switching to a pre-paid cell phone plan. Be sure to check out Straight Talk, a service provided by TracFone Wireless Inc., the largest no-contract cell phone provider in the U.S. Straight Talk offers a pre-paid, no-contract “unlimited plan” for $45 a month to receive unlimited, nationwide anytime talk, text and data with calls to 411 at no additional charge.
  5. Upgrade Your Plan: If despite diligent monitoring you are still getting right up to, or exceeding, your usage limits, it may be prudent to upgrade your plan. Check out BillShrink, a free, independent service that analyzes your cell phone bill and sorts through 10 million options from AT&T, Sprint, T-Mobile, and Verizon to find the best cell phone plan. While BillShrink can be a useful tool, keep in mind that the service only analyzes a small number of cell phone carriers and does not include pre-paid plans.

The Future of Overage Fees: The FCC's "Bill Shock" Agreement

Wireless carriers receive almost 50 percent of their revenue from overage fees. However, in light of the new "bill shock" agreement between wireless carriers and the FCC, that will change. Under this agreement, participating carriers (representing more than 97 percent of the nation's wireless carriers) have agreed to provide customers with advance alerts when they approach their plan limits.

The carriers' agreement with the FCC covers voice, data, and text overages as well as international roaming fees. Participating carriers have until October 17, 2012 to implement an alert system for at least two of the four potential sources. By May 17, 2013, participating carriers must implement an alert system for all four potential sources. Some carriers have already started to implement these alerts.

The following chart, available on the FCC 's newly launched "bill shock" website, shows carriers’ status:

Some major carriers including AT&T, Sprint, T-Mobile USA, and Verizon Wireless have already implemented limited overage alerts to customers. If you use these carriers, click on the appropriate link (above), to see how the alert system works. Follow other carriers’ progress at the FCC's “bill shock” website. Ask your current cell phone carrier and potential carriers whether they are participating.

Outrageous Overages: How to Avoid Cell Phone "Bill Shock"