Choosing the right cell phone plan is as important, if not more important, than choosing the right cell phone. Dollar-per-minute overages, a lax assortment of features, and inadequate network coverage can cost your business hundreds of dollars. That cost gets multiplied by the number of phones your staff requires.

The 200 million cell phone subscribers in the U.S. last year spent a total of $113 billion on service, according to the Cellular Telephone Industry Association. But the use of wireless services by U.S. businesses -- which have expanded to data, e-mail and Web browsing -- led to an estimated $15 billion in productivity gains by companies, a 2006 CTIA report says.

Since cell phone service can help companies be more productive by allowing traveling employees to make calls -- or send e-mail -- from the road or from home, it's vital to select a calling plan that best suits your business needs. In order to figure out what type of service is best for your company, consider some basic questions about your business before signing up:

How many phones do we need?

All major carriers -- including Verizon, T-Mobile, Sprint Nextel, etc. -- offer business plans geared towards multiple phones, which include three-way talking and other bonus features. Not all of them support unlimited off-peak minutes (traditionally from 9 p.m. to 6 a.m.), although they can offer discounts based on the number of phones.

If only a few phones are needed, consider doing a (sometimes cheaper) family plan for your business. Family plans simply encompass two or more cell phones. The base plan will cost a few dollars more than a single phone setup, but adding additional phones as your business expands is an easy and inexpensive process. Be aware that some plans require that every member get the same type of phone.

Another alternative method is the so-called "circle" option, which allows you to put certain people -- maybe your employees or top clients -- in your calling circle and call them for little-to-no charge. It requires that they have the same carrier.

Will most business be done during the day, night or weekends?

This is perhaps the most crucial decision in choosing the right cell phone plan. All carriers give a baseline of minutes per month, sometimes called a "bucket," that can be used anytime. There are generally two types of plans: anytime plans and anytime plans with bonus minutes.