If I have verizon and in the no coverage area but can still make calls

Your rate plan defines an area called your home area, which, depending on your plan, can be a city, a geographic region, a multistate area, or the whole country. If you use your phone outside this home area, you are said to be roaming. All phones have some visual display to let you know that you're no longer in your home area.

When you roam, airtime rates are typically much higher than your plan rate, and you may even be getting your service from a different carrier. In addition to your roaming rate, long-distance charges and--in some cases--further usage fees may apply as well.

Fortunately, all carriers have created rate plans that offer large home areas, sometimes as large as the whole country. These rate plans, such as AT&T's One Rate, VoiceStream's North American Neighborhood, and Sprint PCS's Free and Clear plans, can make roaming a nonissue. These plans may include long distance as well, and while they are initially more costly than local usage plans, you won't end up paying a lot in roaming fees and roaming long-distance charges. If you travel frequently, you should certainly consider these options.

It's worth noting that some carriers do not have coverage everywhere in the nation. If your phone picks up another carrier's signal, you may still accrue roaming fees even if you are technically on your carrier's national plan. In these cases, individual carriers may apply charges in a variety of ways: they may have a standardized "off-network" rate, or they may convert the charges and subtract minutes from your national plan. Or, you may be charged the roaming rate offered by the carrier providing service where your calls were made or received. Check your rate plan information carefully to define what charges you can expect.