At Chris' Liquor on South Lamar, general manager Stephen King has seen his share of minors trying to pass off as being older than 21.
Some of them using fake ID's.
"All of which I believe I've caught," King said.
That's just one of the ways some minors try to pull the wool over the cashier's eyes. And they're not always skilled in deception.
"Sometimes the customers will get nervous and they may sweat or they may make funny faces. That really set them apart and the way they act when they're inside the store," King said.
Chris Porter with the TABC says as students come back to UT after summer break, starting in early September the agency will be doing some under-cover "sting" operations at Austin-area liquor stores and convenience stores along with other university towns in the state like Dallas, Houston and College-Station.
"TABC does see an upturn in the amount of minor alcohol charges that we see so that means retailers are selling alcohol to minors unknowingly, perhaps knowingly," Porter said.
Here's how it works: Undercover TABC agents will accompany a volunteer -- under 21 of course -- into a store. And from afar, they'll see what happens at the register.
"That minor attempts to purchase the alcohol and they use their actual Texas ID during the transaction. And when asked about their age, they are required to tell the truth about their age, so they can't misrepresent themselves to the retailer," Porter said.
The agents will come back later that day and let the retailer know about the violation and then the retailer will be under TABC scrutiny for up to a year after that -- both under-cover operations and open inspections.
"They could possibly see a suspension of their alcohol license or they could be asked to pay a monetary fine, it just really depends on the violation itself. The employee which sells the alcohol to the minor could also face charges up to a Class A misdemeanor," Porter said.
Porter says the majority of the retailers in Texas want to do the right thing. This operation is to catch those that don't.
A similar sting over spring break resulted in about 9 violations here in Austin according to Porter.
King with Chris' Liquor says this type of investigation is a good idea.
"We're not in any rush to make any mistakes. We're here until 9 pm and so making sure we do our job accurately is important to us," King said.
The TABC says they offer free education for retailers who want to help their employees prevent the sale of alcohol to minors.
That includes being able to tell when an ID is fake.