June 22 - Over the last few years, new battle lines have been drawn in the war over taxing Internet sales.

States where revenue is climbing back at a microscopic rate from recessionary lows are calculating the money they have forgone by not collecting sales taxes on goods sold by online mega-retailers such as Amazon.com Inc and Overstock.com Inc.

An employee of Amazon works at the storage facility of Amazon in Germany (Photo: Corbis)

But just as each state is unique, the fights differ from place to place. Most disputes revolve around whether a worldwide company has a physical presence in a state or if it sells goods through smaller companies, also known as affiliates, in the state.

Meanwhile, companies fear they will be entangled by the wide variety of laws within and among states, having to work to comply with 50 separate tax codes.

"In fact, only Congress has the authority to let states require the collection of the billions of dollars in uncollected sales tax revenues from e-commerce transactions," wrote the Council of State Governments in a recent report.

A 2009 University of Tennessee study estimated annual national state and local sales tax losses from Web commerce will grow to more than $11 billion in 2012 and could be as much as $12.65 billion next year.

The study found over a five-year span starting in 2007 that California would lose the most money, at $8.7 billion. Arizona, Florida, Georgia, Idaho, Louisiana, Minnesota, New York, Ohio, Pennsylvania, Tennessee, Texas, and Washington each would lose more than $1 billion in revenue.

Below are the recent developments in the states' battles over what some call "The Amazon Tax."

California

The state legislature included in its budget a requirement for retailers such as Amazon to collect sales taxes. Governor Jerry Brown vetoed the budget but said the sales tax "is a common-sense idea."

South Carolina

In April, the House defeated an amendment that would have provided a five-year sales tax exemption to Amazon in exchange for the online retailer building a distribution center in the state. Amazon canceled plans to build in South Carolina.

Arkansas

In April, Governor Mike Beebe signed a law requiring Amazon and Overstock along with other Internet retailers to collect sales taxes on purchases if they generate more than $10,000 a year in sales to Arkansas residents through local affiliate web sites. Overstock told its affiliates in the state they would no longer do business with them unless they relocate to a state without a tax law.

Illinois

In March, the state began requiring retailers and their affiliates to collect sales taxes on purchases by Illinois residents in a "click through" law. Amazon has threatened to cut off affiliates in the state.

Colorado, North Carolina, Rhode Island

Amazon terminated its affiliate programs in the three states after they also passed "click-through" laws.

Texas

In September, Texas Comptroller Susan Combs sent Amazon a bill for $269 million for uncollected sales taxes, interest and penalties for the period December 2005 to December 2009. Combs says Amazon has a presence in the state and must pay sales taxes. But Amazon countered that its location, which is owned by a subsidiary, does not constitute the kind of physical presence the state's tax law requires. It announced it would close its distribution center, shedding 119 jobs.

Tennessee

Amazon is finishing a distribution center in Chattanooga and plans to construct another site nearby in Bradley County. The company will hire more than 1,400 full-time workers and more than 2,000 part-time workers for its centers. Tennessee officials say taxpayer confidentiality laws prevent the state from stating if it gave Amazon an exemption from a law requiring any retailer with a physical presence in the state to collect sales taxes on in-state purchases.

New York

The state passed legislation in 2008 requiring Amazon to collect sales taxes. Amazon is challenging the law in court.

Washington, Kansas, North Dakota, Kentucky

Amazon collects taxes in these four states because it has a physical presence there. Washington is its headquarters. Kansas and North Dakota are home to its call centers, and the company processes returns in Kentucky.

Utah

Overstock collects taxes there because it is based in the state.

SOURCES: Reuters reports, Southern Legislative Conference of the Council of State Governments (Editing by Jeffrey Benkoe)