the appropriate state through a certified service provider. SSTP has also been in the forefront of an effort to push Congress to amend the laws to make collection of sales tax less burdensome. In fact, in May 2013, the United States Senate passed a bill that would give the states authority to require sellers to collect sales tax on out-of-state sales. The House of Representatives must still pass the bill and send it to the President of the United States before it becomes law. States may also work with adjacent states via interstate use tax agreements. These agreements allow states to exchange tax audit records from businesses that have shipped goods to out of state consumers. Reciprocal states will then use those records and send a tax bill including penalties and interest to the individual taxpayer. States have also pursued their collection efforts through the court system. In 2007, a California appeals court ruled that Borders Online owed California sales tax for online purchases that the store failed to collect from 1998 to 1999 since customers were able to return merchandise bought on-line to Border's retail stores in California. Exemptions Exemptions are typically offered based upon the type of customer: Resale - Resale certificates are the most commonly used of the sales tax exemption certificates. Sales taxes are applied to retail sales and so sales for the purpose of reselling are exempt to avoid double taxation. Reselling and wholesaling account for $844 billion of the American GDP, or 3.3%. Manufacturing - Manufacturing exemption certificates generally apply to manufacturers of tangible personal property, industrial processors, and refineries that produce tangible personal property for sale at retail. Each state outlines specific equipment and/or consumables that are eligible for the exemption. Estimates show (as discussed further in the Statistics Section) that $2.08 trillion and 12.5% of GDP is associated with the manufacturing sector. Agricultural - Agricultural exemptions are generally applied to sales of tangible property that will be utilized in farming, raising livestock, and maintaining agricultural land. According to the US Department of Agriculture, $412.3 billion of GDP relates to agriculture, and $5.816 trillion of tangible assets are in use for agricultural purposes. Estimates derived from gross sales of sampled states with exemption certificates that were annualized and stratified show that $45 million of state reported gross sales are associated with the agriculture sector. Government - The federal government is exempt from sales