COLUMBIA, Mo. -

The back-to-school tax-free holiday starts Friday.

Certain back-to-school purchases such as clothing, school supplies, computers, and other items as defined by the statute, are exempt from sales tax for the weekend of August 3.

There are eight counties participating in this holiday. Those include: Macon, Randolph, Monroe, Pettis, Miller, Maries, Gasconade, and Montgomery.

The rest of Mid-Missouri is not.

"The city of Columbia has actually never participated in the tax-free weekend," says Lynn Cannon, assistant director of finance for Columbia.

The city most likely never will.

The holiday began in 2004 as a temporary holiday. Once it became a permanent event in 2006 the city went ahead and opted out of all future tax holidays by signing an ordinance.

However, even though some cities have opted out, consumers can still participate by getting state sales tax taken out. Check out specific tax rates for your area.