Thinking about changing phone companies? Whether you're considering moving between traditional phone companies, replacing your landline phone with a cell phone or moving to a feature-rich Internet telephone company (VoIP), you can take your number with you.

		David Radin, a free-lance writer for the Post-Gazette and consultant, helps his clients meet business/technology challenges -- but they're not always easy. You can contact him at www.megabyteminute.com.

Yet, despite the fact that the process to move your number between carriers has been in place for years, it's still not a perfect science and is fraught with potential problems. I found out the hard way, when I tried moving my number from one VoIP provider (Verizon VoiceWing) to another (Vonage). Instead of taking the expected 10 to 20 days, it took four months, hours of time and an aggressive stance with both vendors.

Perhaps the problem was partially due to trying to move between VoIP services instead of from a traditional telephone account. There aren't many people doing that yet. According to Brooke Schulz, senior vice president at Vonage, the vast majority of the 18,000 numbers they move every week are from a traditional landline service such as Verizon or AT&T, and go smoothly. That makes sense because there are more than 200 million traditional telephone lines in the United States and only 6 million to 7 million VoIP lines.

The process of moving a number to a new service provider is complicated by the fact that there is no visibility in the process and no financial incentive for the company that is losing the business.

Ms. Schulz considers numbers to be a monopoly, with whoever owns the number having a vested interest in keeping that number -- and your business -- and no financial interest in helping the process go through.

Part of the problem is who "owns" the number. While you may think you do, it's actually owned by the phone company, which is defined as either a Baby Bell or as a competitive local exchange carrier (CLEC). When a VoIP company gets in the loop, it means contracting with a CLEC that does business in your local market, because most VoIP companies do not qualify as CLECs. So when you ask to move your number to a VoIP vendor, it puts a request into the appropriate CLEC partner, which sends the request to a third-party clearinghouse or directly to the phone company that originally owned your number.

Once the request has been sent, there is no tracking mechanism between companies. So if there are any problems, you can't tell where the problem happened. In my case, Vonage thought the request was being turned down by Verizon. However, Verizon says it never received the request from Vonage.

If the vendor that originally owned your number doesn't cooperate with the new vendor, you have little recourse -- a problem exacerbated by the fact that you can't cancel the number, then pick it up from the other company. That's a sure-fire way to losing it.