A financial planner reveals the most common money mistake 30-somethings make

But with these transformative events comes added responsibility, marking one of the biggest diversions from the carefree days of your 20s: Now, other people depend on you.

However, failing to prepare financially for the future, particularly in terms of life insurance and estate planning, remains the most common money mistake 30-somethings make, according to Sophia Bera, CFP and founder of Gen Y Planning.

"In your 30s a lot of people have kids, a lot of people are married, have homes, our lifestyle is a little bit more expensive, and we're also responsible for other people," Bera told Business Insider during a Facebook LIVE. "And oftentimes we are underinsured in terms of term life insurance."

Bera recommends getting a term life insurance policy that's seven to 10 times your salary - enough to be able to cover your income, pay off a mortgage, and take care of your kids if anything were to happen to you.

Why term life insurance instead of whole life insurance?

"The reason is because [whole life insurance] is very expensive and it offers a much smaller amount of coverage for a much higher premium," Bera said. "Insurance agents will try to pitch it as an investment tool. However, I think we should keep our saving for retirement or our saving for emergencies separate from our insurance needs."

She goes on to explain that term life insurance, on the other hand, allows you to get a large amount of insurance for a smaller monthly premium, but it only covers you for a period of 20 to 30 years.

"That amount of coverage is covering you when you're the most vulnerable," Bera said. "When your kids would need you, when you need money to live off if something were to happen to you, where you'll be able to pay off your mortgage, or pay for your kids' college. After that 20 year term is up, generally you're in a very different financial position."

It's also a smart idea for 30-somethings to draw up basic estate planning documents, such as putting a will place, naming a guardian for your children, and setting up powers of attorney.

At 30, it's easy to feel invincible. But the future is always looming, and a few hours spent planning now can make all the difference 50 years down the road.

Watch Bera's full Facebook LIVE here: