The 6 Biggest Financial Mistakes to Avoid in Your 30s

UPDATED: April 8, 2024
PUBLISHED: April 8, 2024
Two women in their 30s drinking lattes and eating avocado toast to exemplify Money Mistakes Millennials Make

Thirty-something millennials have a lot on their financial plate. For many, it’s a decade during which they are buying their first home, having children and upgrading their lifestyle. “They’re not sure what to do and how to allocate their funds,” says Kevin Mahoney, CFP and the Washington, D.C.-based founder and CEO of Illumint, which specializes in financial planning for millennials. “It could be down payment money for a home, putting [funds] toward a young child’s education or investing in retirement. There are so many choices at this phase of life—especially when you haven’t had those options before.” 

To help navigate these decisions, here are the most common financial mistakes to avoid in your 30s, according to financial planners. 

1. Allowing lifestyle creep

“Spending is so visible because of social media and the internet,” Mahoney says. That keeping up with the Joneses can lead to expenses surpassing income—and the debt that comes with it. A survey from found that millennials carry the highest debt load—13% of that age group have accrued $10,000 to $30,000 in debt. However, it’s not just lifestyle creep that’s causing this growing debt. 

The same study from found that one in three credit card holders in the U.S. have maxed out their credit cards to cover expenses due to inflation. Mahoney says managing lifestyle creep and navigating inflation is a matter of putting your money where your values lie. “It’s about understanding the expenses that bring your family joy and spending money on [items] that are of a higher value to your family,” he observes.

2. Pursuing home ownership as a financial investment

Thirty-somethings are delaying buying a home. In 2023, the average age to buy a home leapt to 36—the oldest age on record and three years older than in 2021. Whereas many previous generations looked at home buying as a stable, long-term investment, today’s buyers are facing a different picture. 

“I discourage people from going into that process with the idea that it’s an investment, especially in a challenging real estate market,” Mahoney says. “It can lead to more rash decisions that can require unwinding or just personal headaches and disappointments.” Instead, he suggests buying a home as a lifestyle choice based on personal or family needs. 

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Chloe Moore, CFP and the Atlanta-based founder of Financial Staples, also cautions clients against buying a house that’s beyond their financial means. She advises her clients to have a full picture of the total cost involved in owning a home, which includes a down payment, mortgage, homeowners insurance, property taxes and ongoing maintenance and repairs. 

3. Not saving enough for retirement and not diversifying investments

Saving the right amount for retirement varies based on factors such as lifestyle, time horizon and available resources, such as a pension. Financial experts agree the minimum starting point for retirement funds is meeting any available employer match. Moore suggests pushing beyond that to set aside 20% of the gross income. 

Beyond these retirement fund basics through an employer, people in their 30s may also want to start thinking about diversifying their savings.

For example, in addition to an employer-established 401(k), they may want to invest in a Roth IRA and brokerage accounts if extra income allows. How aggressively or conservatively to invest those funds involves weighing personal risk tolerance and individual retirement plans. 

4. Not planning for the expense of having children

As with home buying, millennials are having children later in life. While the average age in the U.S. for a first-time mother to have a child is still in her 20s, it has increased by two years, from 25.6 in 2011 to 27.3 in 2021.

Financial readiness is one factor in people’s decision to have children. Even then, Moore says parents are often unprepared for the expenses of having children. “They don’t realize how much children are going to change the household budget and make adjustments ahead of time,” she says. 

She advises researching and talking to friends and family about what expenses to expect and making these adjustments before the arrival of the first child or subsequent children.  

Once children enter the picture, parents must weigh financial priorities. “There are tradeoffs. Are they going to pay off their student loans or save for their kids’ college? Are they going to pay for daycare or summer camps?” Mahoney asks. 

He recommends setting up different types of savings vehicles, such as a 529 college savings plan or a separate savings account for summer camps, and making small contributions, then adjusting as opportunities for growth present themselves. Overall, he says, “The element I would most love for people to include is the concept of giving themselves some grace.”

5. Putting off getting life insurance

Moore recommends her clients invest in private policies for life insurance in their 30s. Employers often provide life insurance policies; however, these may not be sufficient for an individual’s needs. As people age, she points out, they may encounter health issues that can make finding a policy more difficult or result in paying higher premiums. Instead, she recommends getting life insurance while many are still in a healthy phase of life.  

6. Not building greater income

Many financial factors are beyond an individual’s control—such as the housing market and the stock market. However, “One of the factors you can control that moves the needle the most over the long term is [income],” Mahoney says. He recognizes that while everyone would like to earn more money, that doing so can involve courage and savvy. 

Building income may mean asking for a promotion or a raise, negotiating a higher salary at a new job or asking for stock options as part of a total benefits package. “It can be slow-moving and involves a little bit of personal risk and disappointment… [but] it’s a very powerful lever to pull,” he says.

Photo by Jorge Argazkiak/