Even before reaching their 30th birthday, some 70 percent of Americans are already making huge credit mistakes and it is affecting their credit rating, according to a survey conducted by Credit Karma.

At least 1,000 people between the ages of 31 to 44 participated in a survey, where it was revealed that two-thirds of respondents have had a "credit fumble" before they were 30 years old. These incidents include missing payments, overspending on credit cards, amassing large credit card debts and defaulting on loans, according to CNBC. Credit experts are concerned about the impact this will have among young consumers in the next seven to 10 years.

"I think what a lot of people don't realize ... is how a missed payment can stay on your credit," said Bethy Hardeman of Credit Karma. "It can be one mistake that you don't think is a big deal that can cost you thousands in the long run."

Recovering from bad credit takes years, thus making it harder for a person to apply for more credit cards, car loans and a mortgage with good interest rates. It could also affect their chances of getting an apartment or a job as the vetting process could include credit checks, according to Forbes.

"There's a complete lack of education," said Ken Lin, Credit Karma CEO. "[Your credit] isn't something you worry about six months before you buy a car. It's something you have to think about as soon as you're an adult."

Of the respondents, 50 percent said they had their first credit card at age 21, while 72 percent stated they didn't know much about managing personal finances while in college, including the long-term consequences of taking credit or loans. But the experts say that this can be corrected and bad credit habits can be broken with proper education.

Credit Karma also suggested that colleges and universities teach their students to better understand their "credit life cycle." The agency has been working with several schools to address this.