NEW YORK (CNN/Money) - Can't bear to part with your cell phone number? Well, after November 24 you won't have to.

On that date, new rules set by the FCC will let customers in the nation's 100 largest markets take their local cell phone numbers with them if they switch to a new wireless carrier.

Industry studies predict that about half of the more 150 million cell phone accounts in use will switch to new carriers within the next year.

Portability may sound good for consumers as companies flood the market with attractive offers. But there may be some reasons why you should consider waiting.

Customers should pick the carrier before figuring out which calling plan is right for you by soliciting friends opinions on certain carriers. Take a look at www.myrateplan.com and www.cellupdate.com for additional assistance.

Another important step when considering changing carriers and plans is to assess your cell phone use. Whom do I call? How often do I call? Where do I call (overseas versus local)?

And customers should not cancel their service until they sign up with the new carrier and complete the switch or porting process. If you cancel your current service first, you may lose the ability to transfer the number. Once a porting request has been made, the old carrier cannot refuse to port a number.

Have a recent phone bill available with all your necessary information in front of you when you are ready to change carriers -- it could speed up the switching process.

You may already be paying for portability and aren't even aware of it; some cell carriers are tacking a fee onto monthly bills in advance of the November deadline in preparation of transferring the numbers. These fees range from a few cents to a little over a dollar, depending on the carrier.

CNNfn's Gerri Willis shares tips on what to consider before switching cell phone carriers. Play video (Real or Windows Media)

The FCC says carriers are allowed to charge consumers for number porting, though the new carrier could agree to pay the transfer fee as a way to entice customers. Ask the new carrier if it has such a policy.

Consumers are still obligated to pay any early termination fees and any outstanding balance owed to the old carrier. Don't forget you get to keep your phone number, not your phone, so be sure to factor in the cost of buying a new one.

Carriers are expected to cut prices and beef up promotions to attract customers. While this may be a good thing for consumers, Michael King of research firm Gartner says as the phones and plans become less and less expensive, a reduction in customer support services may follow.

The Management Network Group, a consulting firm for the communications industry, says the wireless industry should be prepared to handle approximately 30 million porting requests or 60 million transactions during the first 12 months, since each request must be processed by two wireless providers.

The firm also found that each wireless provider needs to be able to handle a peak of 800,000-to-2.3 million porting requests per month through June 2004, when portability expands nationwide, which underscores the need for the providers to have their systems and staff fully prepared.

With so many moving pieces involved, there is always the concern whether the providers will get it right the first time. And while the goal is to be able to transfer a number within 2-1/2 hours, there is always that chance of a delay at the beginning.

Some experts say wait until after the November 24th date, and let the system take care of itself before you make the switch. November and December are very busy times for carriers due to the holiday season.

The FCC has also opened the way for consumers to have their home phone numbers transferred to their mobile phones, which also goes into effect Nov. 24. You will be able to transfer your landline number to a cell phone, including area code, as long as you are within your carrier's coverage area.

But you may want to hang onto your wireline for emergency situations. When you call 911 from your wireline, the 911 service knows where you are calling from, whereas with cell service you have to tell them. In the event of a major blackout, cell phones will only last as long as their battery does.  

Gerri Willis is the personal finance editor for CNN Business News. Willis also is co-host of CNNfn's The FlipSide, weekdays from 11 a.m. to 12:30 p.m. (ET). E-mail comments to 5tips@cnnfn.com.