Andrei Stoica, an 18-year-old from Portland, Ore., got banned from the ride-hailing app Lyft his sophomore year of high school.

“It was the last day of school,” Stoica told MarketWatch. He ordered a car to get home, and the driver asked if he was 18 before he got into the vehicle. When Stoica said no, the driver told Stoica not only that he couldn’t drive him but also that he would report him to Lyft LYFT, -0.74% , which has a policy against minors using its services.

About 45 minutes later, Stoica saw his Lyft account had been suspended.

Neither Lyft nor Uber UBER, -0.59% allows people under 18 to ride without a guardian. Uber declined to comment on how often drivers enforce the age policy, but a representative said the company looks into reports of underage passengers, and drivers who give rides to minors risk losing access to the app, as do under-age riders. Lyft did not respond to a request for comment.

But some teens and parents who are regular users of the apps said they either had no idea about the age requirements, or rarely saw them enforced.

In fact, Uber is currently wrapped in controversy for not following its own rule.

On January 10, 12-year-old Benita Diamond died by suicide early in the morning at a closed parking garage in Orlando, Florida. She got there in an Uber after using her mom’s phone to download the app and paid for the ride with a gift card she got for Christmas, her family said. Her parents blame the company for their daughter’s death and announced last week that they’re considering suing. They say the driver should have asked her age given the company policy. An Uber representative said the company is investigating the incident.

Uber’s age policy isn’t easy to find

Several teens told MarketWatch they can easily use Uber without a guardian and have never been questioned about their age.

When you create a rider profile on the app, the company asks for a name, an email address, a phone number, and a password — but not for a birth date. Fine print under the “Sign Up” button reads, “By clicking ‘Sign Up,’ you agree to Uber’s Terms of Use and acknowledge you have read the Privacy Policy.” Users must click on a link to see the 5,500-word Terms of Use, which state that riders must be 18 years old to have an account.

“I had no idea there was a minimum age requirement,” Neal Patel, an 18-year-old who lives in the suburbs of Chicago, told MarketWatch. He said he first started taking Ubers on his own when he was 15, mainly to local restaurants or to the train station so he could get into the city. He’s never been asked his age, he says.

Alexandra Lachmann, an incoming first-year at New York University who grew up in a New York City suburb, had a similar story. She’s been riding in Ubers and Lyfts alone or with friends since she turned 13. She’s never been questioned about her age and had no idea she was supposed to be 18 to get in an Uber alone.

Some parents who rely on Uber said they had no idea minors aren’t allowed

Parents also told MarketWatch they were unaware of the policy.

Dina Brewer, a lawyer and mother of three in central New Jersey, said she did not know passengers had to be 18 to ride in Ubers alone. She lets her kids take the cars and thinks parents, not ridesharing companies, should be able to decide “whether their kids can use Uber at 15 or at 18.”

A number of other parents said they were aware of Lyft’s and Uber’s age restrictions but work to avoid them out of necessity — and most drivers don’t resist.

Lydia Wilbanks says she will let her 16-year-old daughter get in Ubers alone as long as she can track the car’s location on her phone. “I’m aware of the rule,” she told MarketWatch. “But what does a working single mom like me do when I have a conflict in my schedule? I live in Atlanta and cabs just aren’t an option.”

“ ‘Since I can’t be everywhere all of the time, it has helped me quite a bit. I honestly do not know what I would do without Uber.’ ” — — Single mom Jennifer Rice, Knoxville, Tenn.

Another single mom, Jennifer Rice, who lives in Knoxville, Tennessee, and works as a publicist, said she sometimes refers to Uber as her “co-parent.” “Since I can’t be everywhere all of the time, it has helped me quite a bit,” Rice told MarketWatch.

She’ll often send her kids to school in an Uber. She told MarketWatch that a few drivers have asked for her kids’ ages and then canceled the ride, but that’s “rare.” And whenever it has happened, she’s simply waited a couple of minutes and called another car.

“I honestly do not know what I would do without Uber,” she said.

Some drivers aren’t clear on the age policies

Rideshare drivers who spoke to MarketWatch said it’s unclear whose responsibility it is to verify a passenger’s age. The age policies for both Uber and Lyft state that users must be 18 to sign up for an account — though users don’t have to enter their birth date when they sign up — so presumably anyone using the app is of legal age. Drivers can ask for ID if they suspect a rider is under-age, but they’re not required to by either Uber or Lyft.

Dylan Himmerich, a Lyft and Uber driver in Berkeley, Calif., said, “Many parents order rides for their kids and expect drivers to accept them,” referencing what both Rice and Wilbanks do regularly. Himmerich will question these kids about their age and deny them a ride if they aren’t 18, but he says his approach isn’t common. “Plenty of drivers just go against the policy and accept them anyway.”

Dylan Himmerich, who drives for both Uber and Lyft, says he's denied rides to under-age users. Dylan Himmerich

Chad Stevens, an Uber driver in Baton Rouge, Louisiana, said he knows he cannot drive anyone under-age and he has asked passengers to present ID before. But he’s “not sure if Uber requires this.”

He thinks creating an Uber account should be more difficult than it currently is for minors. “You shouldn’t be able to create an account if you’re underage, but I just created one for my 11-year-old son, then deleted it,” he said.

“A driver’s license scan would be a simple fix to this,” Himmerich said. Scooter companies, like Bird and Lime, are already doing this to verify their users’ ages.