WASHINGTON — A monthly phone bill of $50 includes as much as $10 in taxes. And some in Congress warn that consumers soon could be hit with similar assessments for high-speed Internet access.

For nearly a decade, the lines carrying the Internet into homes and businesses have been a virtual tax-free zone. But that could change Nov. 1, when a federal ban on Internet access taxes expires.

Almost everybody agrees the politically popular moratorium should be extended to encourage continued investment in the high-speed lines crucial to delivering phone calls and video. But changing Internet usage has complicated the issue, threatening to derail an extension and raising the specter of local officials engaging in a land-rush-like race to enact new taxes for surfing the Web.

"If Americans want to know what their Internet access bill will look like if this moratorium expires, all they need to do is look at their phone bill," said Sen. John McCain, R-Ariz., who wants to permanently extend the moratorium. "Taxes and government fees add as much as 20 percent to Americans' telephone and cell phone bills. We can't let that happen to the Internet, which is likely the most popular invention since the light bulb."

But as phone and TV services increasingly are delivered over the Internet, state and local governments worry that more of their tax revenues will disappear because of the federal moratorium. They oppose the permanent extension championed by McCain and a slew of lawmakers, along with Don't Tax Our Web, a coalition of major telecommunications, computer and Internet companies, including AT&T Corp., Google Inc. and Time Warner Inc.

Instead, the U.S. Conference of Mayors, the National Governors Association and other local government groups want to narrow the definition of Internet access put in place in 1998, which could be interpreted to cover anything delivered online, and to make the extension temporary in case technology again overtakes the law.

The groups also want Congress to continue to allow nine states — Hawai'i, New Hampshire, New Mexico, North Dakota, Ohio, South Dakota, Texas, Washington and Wisconsin — to collect Internet access taxes in place before 1998. Most of those states apply sales taxes to Internet access charges, tacking an average of about $2 on to a monthly $40 broadband bill. The issue is different from the problem of applying the patchwork of local sales taxes to online purchases, which none of the moratorium proposals address.

There is strong bipartisan support in Congress for a permanent extension of the existing access tax ban, which the White House also supports. But two former governors, senators Thomas R. Carper, D-Del., and Lamar Alexander, R-Tenn., are pushing a compromise backed by state and local governments that a Senate committee will consider today.