Efforts to impose sales tax on internet purchases will take a step forward on October 1 when the 18 states admitted in July into the governing board of the Streamlined Sales and Use Tax Agreement begin to operate under that agreement, reports Internet Retailer. The states hope to win support for new federal tax-authorization legislation.

Proponents still have a long way to go to overcome opposition and win congressional support. Skeptics say even if states agree to definitions of products to be taxed, they may still differ in their interpretation of those definitions.

But the more states join the Streamlined Sales Tax project (SST), as is expected, Congress would be more likely to act.

The 18 states have agreed to a common set of definitions and procedures for taxing multiple product categories under the SST, which is designed to show that a multi-state system of collecting sales tax is possible. Current law allows states to tax internet retailers on transactions only if they maintain a physical presence in the state where a buyer makes an online purchase.