Starting Oct. 1, many Internet shoppers in Michigan may see an unusual item on their order summary page — Michigan sales tax.

In January of 2015 Gov. Rick Snyder signed the Main Street Fairness Act, which more explicitly defines which out-of-state companies will be compelled to collect Michigan sales tax.

It is not yet clear whether the change will affect purchases from the nation's top online retailer, Amazon. By most accounts, Amazon does not have a warehouse or fulfillment center in Michigan and so may be exempt from the new law.

The complication will come with third-party sellers on Amazon who may have a nexus in the state if they use an agent or warehouse here to complete a sale to a customer in Michigan.

“Note that this bill clarifies that storing goods in a warehouse, or contracting with installers or repair people will now specifically constitute a sales tax nexus with Michigan,” said Mark Faggiano, founder of TaxJar, a company that helps retailers with sales tax compliance.

Faggiano says a nexus will now also include agents that an out-of-state retailer may use to establish a market in Michigan, under what is known as a “click-through” nexus. He cites an example of an out-of-state seller using a Michigan-based website to sell merchandise.

The Michigan Department of Treasury does not publish a list of registered sellers in the state, and Amazon does not list Michigan as one of the 25 states for which it collects sales tax.

“Nexus” is a legal concept derived from the due process and commerce clauses of the U.S. Constitution. The Supreme Court ruled that a state may compel an out-of-state seller to collect sales tax from in-state customers only if the seller has a physical presence, or nexus, in the state.

With the burgeoning of online sales, many states, including Michigan, have been complaining that they are missing out on millions of dollars in sales tax revenue. Out-of-state merchandise is not exempt from sales tax, but the law does require purchasers to remit an equivalent “use” tax.

Compliance with the use tax requirement is low, according to the Michigan Department of Treasury. The department estimates that up to $444 million worth of use tax will go uncollected this fiscal year.

Diane Yetter, founder of the Sales Tax Institute and president of a sales tax consulting firm, says Michigan is not unusual in passing an Internet tax law. She said many states are waiting to see how tax fairness laws hold up in court.

“This year is probably the biggest year of states enacting these laws and it’s because litigation involving the laws in New York and Illinois came to an end in 2013,” said Yetter.

Yetter believes legal challenges to Michigan’s law are unlikely. It is similar to the law in New York. The high court declined to hear a challenge to that law.

Amazon could not be reached for comment, and Faggiano says the company does not disclose where it has fulfillment centers. TaxJar believes Amazon operates them in 17 states, but not Michigan.

According to its website, Amazon collects sales tax in 25 states. The Michigan Department of Treasury estimates that under the new sales tax law, Michigan will collect an additional $60 million a year in sales and use tax.

By a unanimous vote on Wednesday, the Michigan Employment Relations Commission ruled that the Michigan Education Association’s attempt to restrict school employees' rights under right-to-work violates state labor law and is an unfair labor practice. The MEA, which exercised the restriction under a so-called August window, is the state’s largest teachers union. It is expected to appeal the decision in the courts.

The ruling is the latest development in a 2013 lawsuit brought by four Saginaw public school employees who did not want to be forced to financially support the union as a condition of employment.

The August window is an internal MEA rule that only allows school employees to choose not to pay annual union dues or fees if they submit a request in writing during the month of August. Wednesday’s ruling by the employment commission upheld a September 2014 legal finding by Administrative Law Judge Julia Stern, who said that a union’s private bylaws do not override state law, specifically Michigan’s new right-to-work law.

The case began when Jason LaPorte, Susan Romska, Kathy Eady-Miskiewicz and Matthew Knapp asserted that the union threatened to turn them over to a collections agency when they informed it that they would exercise their right to opt out of paying dues — but did so in months other than August. The Mackinac Center Legal Foundation represented the four school employees.

The employment commission also ordered the MEA to cease and desist from enforcing its rule. It also said the MEA must either strike the rule from its bylaws or amend the bylaws to reflect the ruling. In addition, it ordered the union to stop pursuing collection of union dues from members based on their having left the union outside of the August window.

“If a union is doing a good job and its members are happy with the service it provides, it shouldn’t have to resort to turning the names of those who no longer want to be union members over to collections agencies,” said Patrick Wright, director of the Mackinac Center Legal Foundation.

“Unions do a lot of things,” Wright continued. “They take many policy positions and are involved with many issues at the local district level. Their members should have the right to instantaneously say. ‘Enough is enough; I no longer want to be part of the union.’”

After the employment commission announced its ruling, the MEA posted the following on its website, attributed to union President Steve Cook.

“Only about 2 percent of MEA members resigned this year, a significant reduction over last August’s resignation window. It’s clear that the vast majority of our members are sticking with us, despite the efforts of the Mackinac Center and other extreme right-wing groups to divide our members from their union through continued political attacks on public education.”

“MEA is proud to stand up for our members and help make their voices heard when it comes to decisions that affect the learning conditions of students and the working conditions of school employees. MERC’s decision does nothing to change that.”