Wireless phones and plans are changing constantly and service contracts can be difficult to read. There is no standardized format to help consumers comparison-shop, which makes looking for the right cellular plan very confusing. Here are 15 key questions to ask when shopping for wireless service. Consumers should always remember to select a carrier and a plan first before choosing a phone.

Exactly when are night, weekend, peak, off-peak and "anytime" minutes?
Many plans offer a combination of each of these minutes. Be careful though, because these terms don’t mean the same thing for all carriers. When you use the phone makes a difference in selecting the best plan for you.

Exactly where is "home," "region" and "nation"?
Ask to check out the coverage maps, but note federal regulators no longer require carriers to provide maps. So your best bet is to seek recommendations from friends, neighbors or business associates who drive the same roads and walk the same sidewalks you do before you sign up with any cell phone carrier.

Does nationwide mean the carrier's national network only?
For some carriers, nationwide calling is limited to calling on the carrier's own network, which may be less than true nationwide coverage. That’s why it is important to ask specifically if a carrier has roaming agreements, which increase your ability to get coverage.

Who pays for incoming calls?
Typically, incoming calls are charged against your minutes, but some plans are offering free incoming calls.

What is the price per minute if I exceed the limit on my plan?
It’s important to understand the cost of exceeding your minutes since doing so not only increases your calling costs but also the overall taxes you’re charged. But shoppers should also avoid getting drawn in by a large number of free minutes--if the minutes aren't available when you use the phone, you end up paying more.

How much are roaming charges?
Carriers usually charge additional per minute fees for calls made from another carrier's network. Some have eliminated these fees in nationwide plans. If you are likely to place calls outside your "home" area, be sure you understand the additional charges and whether you should consider a regional or national plan.

Is long distance included?
Some plans include long distance service, others charge additional per minute fees for long distance.

What happens to unused minutes?
Generally, remaining minutes at the end of a billing period are lost. Recently, some carriers have begun offering plans that allow customers to roll over minutes into the next month.

What happens to fractions of minutes?
Most carriers round usage up to the next full minute, even if only a small portion of the minute is used. Some carriers offer plans that round to the nearest second. If you typically use up your minutes, this feature may be helpful.

Can I use my phone with another carrier?
Different carriers' networks are not necessarily compatible with each other, so switching service usually means purchasing a new phone.

What exactly are the “Additional Charges”?
Additional services such as directory assistance, Caller ID, voice mail, text messaging, etc., may be included in the monthly charge or may incur additional charges, depending on the plan. A plan may advertise these services as available, but not clearly indicate the additional charges.

What are the charges to start and end service?
Some plans charge activation fees to begin service and often hefty termination fees to end service before the end of a contract period.

Does this phone also work in the analog mode?
Phones that can work in both digital and analog modes give you more opportunities to get through, which can be especially important when dialing 911 in an emergency. Analog is the common wireless language, which is widely available nationwide.

Can you give me an estimate of the taxes, fees and surcharges with typical usage of this phone?
Remember that these can add up--increasing the bottom line of your bill by several dollars per month. These charges vary depending on where you live and the size of your bill before taxes, but we've seen these charges add as much as 20% to cell phone bills.

Is there a "test drive" period? How long?
Many carriers offer a trial period before stiff early termination penalties kick in. Without a trial run you may find that your chosen carrier has "dead zones" in those spots that you would use your phone most often. Note that there’s often a nominal non-refundable start-up fee.

After your purchase, review your bills carefully, especially the first one to ensure you are charged as advertised.