Solo 401(k) vs SEP IRA: An In-Depth Comparison for Self-Employed Retirement Planning

By Rebecca Lake. May 18, 2024 · 13 minute read

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Solo 401(k) vs SEP IRA: An In-Depth Comparison for Self-Employed Retirement Planning

Self-employment has its perks, but an employer-sponsored retirement plan isn’t one of them. Opening a solo 401(k) or a Simplified Employee Pension Individual Retirement Account (SEP IRA) allows the self-employed to save for retirement while enjoying some tax advantages.

So, which is better for you? The answer can depend largely on whether your business has employees or operates as a sole proprietorship and which plan yields more benefits, in terms of contribution limits and tax breaks.

Weighing the features of a solo 401(k) vs. SEP IRA can make it easier to decide which one is more suited to your retirement savings needs.

Key Points

•   Solo 401(k) allows tax-deductible contributions, employer contributions, employee contributions, and offers the option for Roth contributions and catch-up contributions.

•   SEP IRA allows tax-deductible contributions, employer contributions, but does not allow employee contributions, Roth contributions, catch-up contributions, or loans.

•   Withdrawals from traditional solo 401(k) plans and SEP IRAs are taxed in retirement.

•   Solo 401(k) plans allow loans, while SEP IRAs do not.

•   Solo 401(k) plans offer more flexibility and options compared to SEP IRAs.

Understanding the Basics

A solo 401(k) is similar to a traditional 401(k), in terms of annual contribution limits and tax treatment. A SEP IRA follows the same tax rules as traditional IRAs. SEP IRAs, however, typically allow a higher annual contribution limit than a regular IRA.

What Is a Solo 401(k)?

A solo 401(k) covers a business owner who has no employees or employs only their spouse. Simply, a Solo 401(k) allows you to save money for retirement from your self-employment or business income on a tax-advantaged basis.

These plans follow the same IRS rules and requirements as any other 401(k). There are specific solo 401(k) contribution limits to follow, along with rules regarding withdrawals and taxation. Regulations also govern when you can take a loan from a solo 401(k) plan.

A number of online brokerages offer solo 401(k) plans for self-employed individuals, including those who freelance or perform gig work. You can open a retirement account online and start investing, no employer other than yourself needed.

If you use a solo 401(k) to save for retirement, you’ll also need to follow some reporting requirements. Generally, the IRS requires solo 401(k) plan owners to file a Form 5500-EZ if it has $250,000 or more in assets at the end of the year.

What Is a SEP IRA?

A SEP IRA is another option to consider if you’re looking for retirement plans for the self-employed. This tax-advantaged plan is available to any size business, including sole proprietorships with no employees. SEP IRAs work much like traditional IRAs, with regard to the tax treatment of withdrawals. They do, however, allow you to contribute more money toward retirement each year above the standard traditional IRA contribution limit. That means you could enjoy a bigger tax break when it’s time to deduct contributions.

If you have employees, you can make retirement plan contributions to a SEP IRA on their behalf. SEP IRA contribution limits are, for the most part, the same for both employers and employees. If you’re interested in a SEP, you can set up an IRA for yourself or for yourself and your employees through an online brokerage.

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Diving Deeper: Pros and Cons of Each Plan

As you debate between a solo 401(k) vs. a SEP IRA as ways to build wealth for retirement, it’s helpful to learn more about how these plans work, including their benefits and drawbacks.

Advantages of Solo 401(k)s

In terms of differences, there are some things that set solo 401(k) plans apart from SEP IRAs.

With a solo 401(k), you can choose a traditional or Roth. You can deduct your contributions in the year you make them with a traditional solo 401(k), but you’ll pay taxes on your distributions in retirement. With a Roth solo 401(k) you pay taxes on your contributions in the year you make them, and in retirement, your distributions are tax free. You can choose the plan that gives you the best tax advantage.

Another benefit of a solo 401(k) is that those age 50 and older can make catch-up contributions to this plan. In addition, you may be able to take a loan from a solo 401(k) if the plan permits it.

Advantages of SEP IRAs

One of the benefits of a SEP IRA is that contributions are tax deductible and you can make them at any time until your taxes are due in mid-April of the following year.

The plan is also easy to set up and maintain.

If you have employees, you can establish a SEP IRA for yourself as well as your eligible employees. You can then make retirement plan contributions to a SEP IRA on your employees’ behalf. (All contributions to a SEP are made by the employer only, though employees own their accounts.)

SEP IRA contribution limits are, for the most part, the same for both employers and employees. This means that you need to make the same percentage of contribution for each employee that you make for yourself. That means if you contribute 15% of your compensation for yourself, you must contribute 15% of each employee’s compensation (subject to contribution limits).

A SEP IRA also offers flexibility. You don’t have to contribute to it every year.

However, under SEP IRA rules, no catch-up contributions are allowed. There’s no Roth option with a SEP IRA either.

Eligibility and Contribution Limits

Here’s what you need to know about who is eligible for a SEP IRA vs. a Solo 401(k), along with the contribution limits for both plans for 2023.

Who Qualifies for a Solo 401(k) or SEP IRA?

Self-employed individuals and business owners with no employees (aside from their spouse) can open and contribute to a solo 401(k). There are no income restrictions on these plans.

SEP IRAs are available to self-employed individuals or business owners with employees. A SEP IRA might be best for those with just a few employees because IRS rules dictate that if you have one of these plans, you must contribute to a SEP IRA on behalf of your eligible employees (to be eligible, the employees must be 21 or older, they must have worked for you for three of the past five years, and they must have earned at least $750 in the tax year).

Plus, the amount you contribute to your employees’ plan must be the same percentage that you contribute to your own plan.

Contribution Comparison

With a solo 401(k), there are rules regarding contributions, including contribution limits. For 2023, you can contribute up to $66,000, plus an additional catch-up contribution of $7,500 for those age 50 and older. In 2024, you can contribute up to $69,000, plus an extra catch-up contribution of $7,500 for those age 50 and older.

For the purposes of a solo 401(k) you play two roles — employer and employee. As an employee, you can contribute the lesser of 100% of your compensation or up to $22,500 in 2023 and up to $23,000 in 2024. If you’re 50 or older, you can contribute the $7,500 catch-up contribution in 2023 and 2024 as well. As an employer, you can make an additional contribution of 25% of your compensation (up to $330,000 of compensation in 2023 and $345,000 in 2024) or net self-employment income.

The contribution limits for a SEP IRA are the lesser of 25% of your compensation or $66,000 in 2023 and $69,000 in 2024. As mentioned earlier, there are no catch-up contributions with this plan.

And remember, per the IRS, if you have a SEP IRA, you must contribute to the plan on behalf of your eligible employees. The amount you contribute to your employees’ plan must be the same percentage that you contribute to your own plan.

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Key Differences That Could Influence Your Decision

When you’re deciding between a solo 401(k) vs. a SEP IRA, consider the differences between the two plans carefully. These differences include:

Roth Options and Tax Benefits

With a solo 401(k), you can choose between a traditional and Roth solo 401(k), depending on which option’s tax benefits make the most sense for you. If you expect to be in a higher tax bracket when you retire, a Roth may be more advantageous since you can pay taxes on your contributions upfront and get distributions tax-free in retirement.

On the other hand, if you anticipate being in a lower tax bracket at retirement, a traditional solo 401(k) that lets you take deductions on your contributions now and pay tax on distributions in retirement could be your best option.

Loan Options and Investment Flexibility

You may also be able to take a loan from a solo 401(k) if your plan permits it. Solo 401(k) loans follow the same rules as traditional 401(k) loans.

If you need to take money from a SEP IRA before age 59 ½, however, you may pay an early withdrawal penalty and owe income tax on the withdrawal.

Both solo 401(k)s and SEP IRA offer more investment options than workplace 401(k)s. So you can choose the investment options that best suit your needs.

The Impact of Having Employees

Whether you have employees or not will help determine which type of plan is best for you.

A solo 401(k) is designed for business owners with no employees except for a spouse.

A SEP IRA is for those who are self-employed or small business owners. A SEP IRA may be best for those who have just a few employees since, as discussed above, you must contribute to a SEP IRA on behalf of all eligible employees and you must contribute the same percentage of compensation as you contribute for yourself.

The Financial Implications for Your Business

The plan you choose, solo 401(k) vs. SEP IRA, does have financial and tax implications that you’ll want to consider carefully. Here’s a quick comparison of the two plans.

Solo 401(k) vs SEP IRA at a Glance

Both solo 401(k) plans and SEP IRAs make it possible to save for retirement as a self-employed person or business owner when you don’t have access to an employer’s 401(k). And both can potentially offer a tax break if you’re able to deduct contributions each year.

Here’s a rundown of the main differences between a 401(k) vs. SEP IRA.

Solo 401(k)

SEP IRA

Tax-Deductible Contributions Yes, for traditional solo 401(k) plans Yes
Employer Contributions Allowed Yes Yes
Employee Contributions Allowed Yes No
Withdrawals Taxed in Retirement Yes, for traditional solo 401(k) plans Yes
Roth Contributions Allowed Yes No
Catch-Up Contributions Allowed Yes No
Loans Allowed Yes No

How These Plans Affect Your Bottom Line

Both solo 401(k)s and SEP IRAs are tax-advantaged accounts that can help you save for retirement. With a SEP IRA, contributions are tax deductible, including contributions made on employees’ behalf, which offers a tax advantage. Solo 401(k)s give you the option of choosing a traditional or Roth option so that you can pay tax on your contributions upfront and not in retirement (traditional), or defer them until you retire (Roth).

Making the Choice Between SEP IRA and Solo 401(k): Which Is Right for You?

An important part of planning for your retirement is understanding your long-term goals. Whether you choose to open a solo 401(k) or make SEP IRA contributions can depend on how your business is structured, how much you want to save for retirement, and what kind of tax advantages you hope to enjoy along the way.

When to Choose a Solo 401(k)

If you’re self-employed and have no employees (or if your only employee is your spouse), you may want to consider a solo 401(k). A solo 401(k) could allow you to save more for retirement on a tax-advantaged basis compared to a SEP IRA. A solo 401(k) allows catch-up contributions if you are 50 or older, and you can also take loans from a solo 401(k).

Just be aware that a solo 401(k) can be more work to set up and maintain than a SEP IRA.

When to Choose a SEP IRA

If you’re looking for a plan that’s easy to set up and maintain, a SEP IRA may be right for you. And if you have a few employees, a SEP IRA can be used to cover them as well as your spouse. However, you will need to cover the same percentage of contribution for your employees as you do for yourself.

Remember that a SEP IRA does not allow catch-up contributions, nor can you take loans from it.

Step-by-Step Guide to Opening Your Account

You can typically set up a SEP IRA with any financial institution that offers other retirement plans, including an online bank or brokerage. The institution you choose will guide you through the set-up process and it’s generally quick and easy.

Once you establish and fund your account, you can choose the investment options that best suit your needs and those of any eligible employees you may have. You will need to set up an account for each of these employees.

To open a Solo 401(k), you’ll need an Employee Identification Number (EIN). You can get an EIN through the IRS website. Once you have an EIN, you can choose the financial institution you want to work with, typically a brokerage or online brokerage. Next, you’ll fill out the necessary paperwork, and once the account is open you’ll fund it. You can do this through direct deposit or a check. Then you can set up your contributions.

Additional Considerations for Retirement Planning

Besides choosing a SEP IRA or a solo 401(k), there are a few other factors to consider when planning for retirement. They include:

Rollover Process

At some point, you may want to roll over whichever retirement plan you choose — or roll assets from another retirement plan into your current plan. A SEP IRA allows for either option. You can generally roll a SEP IRA into another IRA or other qualified plan, although there may be some restrictions depending on the type of plan it is. You can also roll assets from another retirement plan you have into your SEP.

A solo 401(k) can also be set up to allow rollovers. You can roll other retirement accounts, including a traditional 401(k) or a SEP IRA, into your solo 401(k). You can also roll a solo 401(k) into a traditional 401(k), as long as that plan allows rollovers.

Can You have Both a SEP IRA and a Solo 401(k)?

It is possible to have both a SEP IRA and a solo 401(k). However, how much you can contribute to them depends on certain factors, including how your SEP was set up. In general, when you contribute to both plans at the same time, there is a limit to how much you can contribute. Generally, your total contributions to both are aggregated and cannot exceed more than $66,000 in 2023 and $69,000 in 2024.

Preparing for Retirement Beyond Plans

Choosing retirement plans is just one important step in laying the groundwork for your future. You should also figure out at what age you can retire, how much money you’ll need for retirement, and the typical retirement expenses you should be ready for.

Working on building your retirement savings is an important goal. In addition to opening and contributing to retirement plans, other smart strategies include creating a budget and sticking to it, paying down any debt you have, and simplifying your lifestyle and cutting unnecessary spending. You may even want to consider getting a side hustle to bring in extra income.

The Takeaway

Saving for retirement is something that you can’t afford to put off. And the sooner you start, the better so that your money has time to grow. Whether you choose a solo 401(k), SEP IRA, or another savings plan, it’s important to take the first step toward building retirement wealth.

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