Bars, restaurants, gas stations and grocery stores are all watched by the Texas Alcohol Beverage Commission.
"We check compliance on all businesses that have a beverage license," Mario Villarreal, Lieutenant of the enforcement division of the Border Region of TABC, said.
Stings are conducted every week to make sure clerks and bartenders aren't serving alcohol to anyone under 21-years of age.
Villarreal said 6,958 stings have been conducted statewide this fiscal year.
Eleven percent of those stings resulted in sales to undercover minors.
"It's important that we go and enforce and look at the laws to sale to minors and intoxicated persons," he said.
Since September, 40 businesses across the Valley have failed minor sting operation.
Cameron County has the highest number of violations with 25 sales.
"The penalty is a fine and suspension of license, and when I say fine we are looking at a fine for a first violation from anywhere from $2,400 to a $3,600 fine on the business," Villarreal said.
These stings are important.
In March, two Edinburg men under the age of 21 died after crashing into a utility pole.
A toxicology report released this week shows the driver was three times over the legal limit.
TABC investigated claims that these minors were drinking at a local bar prior to the accident.
"We looked into allegations of over serving at the Thirsty Bronc," Villarreal said.
The investigation showed they were at the business for less than 30 minutes.
It TMs unclear whether they were served any alcohol but four hours later both crashed and alcohol was found inside their car.
"It's possible that whoever provided the beverages could be facing charges in the future for making alcohol available to a minor," Villarreal said.
TABC encourages businesses to be pro-active at educating their employees on the dangers of serving alcohol to minors.