This weekend is Massachusetts’ annual sales tax holiday. On Aug. 10 and 11, most personal purchases will be tax-free, including online purchases.

But like any other deal, there are a few caveats and exceptions to remember before filling your cart.

Here are a few things to know about Massachusetts’ tax-free weekend:

Not all items are eligible.

There are a few retail items that are not included in the tax-free weekend. You can see the entire list here, but most notable are motor vehicles, gas, alcohol, marijuana and tobacco products. Additionally, pre-made meals are not eligible for a tax-free purchase. 

There is a financial limit to what is considered tax exempt.

Any single item over $2,500 will be taxed in its entirety.

Mark Vautour, a manager at Landry’s Bicycles, said they train staff to handle questions and make sure they’re informing customers about the rules.

“If someone comes in and wants to buy a $6,500 bike, that’s not a tax-free purchase,” Vautour said. “For us, it’s mostly staff training to make sure we’re doing it the right way.”

Eligibility is determined by sales price, not list price. That means if a coupon reduces the cost of an item to less than $2,500, it will not be taxed even it the list price was above that limit.

There is an special rule for clothing, one of the more popular items bought during tax-free holidays. Instead of the $2,500 limit for most purchases, clothing over $175 will be taxed on the cost exceeding that amount. For example, if you buy a $200 dress, only $25 of that purchase will be taxed.

The sales tax holiday only applies to personal purchases.

Making a purchase as a business or corporation will still be taxed, as will any purchase made by an individual for business use. 

You have to purchase this weekend.

Purchases must be made before the weekend ends in Eastern Daylight Time. Even if the item is not delivered before the weekend closes, the purchase remains tax-free.

Some businesses will advertise that you can make a purchase before the sales tax holiday, cancel it, and re-order to avoid paying tax. According to the Massachusetts Department of Revenue, this is not possible if you put down a deposit, prepaid for the item, or in any way agreed to pay for the item prior to Aug. 10.

Rebeca Pereira contributed reporting.