Choosing a Retirement Plan for Your Business Before Year-End

Every fall across Columbus and Central Ohio, successful business owners confront the same calendar pressure. Your company had a profitable year, cash reserves are healthy, and peer conversations turn toward year-end tax deductions. Someone at an industry dinner mentions opening a retirement account before December 31 to reduce taxable income, while another swears by an arrangement they set up years ago.

Before rushing into paperwork, it helps to pause and ask what you actually need this vehicle to accomplish. Deciding on a retirement plan is not simply a matter of picking an account name off a shelf. It is a structural business decision that connects your cash flow, your staffing roadmap, and how you build personal wealth. Understanding why advanced strategies require time before year-end allows you to choose with clarity rather than urgency.

Cash Flow and Contribution Timing Before December 31

The two most common vehicles for self-employed owners and closely held businesses are the Simplified Employee Pension Individual Retirement Arrangement, known as a SEP IRA, and the one-participant 401(k) plan, often called a Solo 401(k). Both tools offer substantial tax-deferred savings, but they treat timing and cash flow very differently.

Under Internal Revenue Service rules for one-participant 401(k) plans, the owner wears two distinct hats: employee and employer. In 2026, you can contribute as an employee through salary deferrals up to $24,500, with an additional $8,000 catch-up contribution if you are age 50 or older. On top of that, your business can make an employer profit-sharing contribution, up to an overall limit of $72,000 across both roles. However, to make employee salary deferrals for the current calendar year, the 401(k) plan generally must be established by December 31.

A SEP IRA operates under different mechanics. All contributions come entirely from the employer side as a percentage of compensation, without an employee salary deferral option. Because of this simpler structure, a SEP IRA can often be established and funded up until your business tax filing deadline, including extensions. If your revenue fluctuates dramatically between seasons and you need to see your final year-end numbers before committing capital, that timing flexibility can be valuable.

How Future Hiring Changes the Decision

Your current headcount might make a plan seem simple today, but your plans for tomorrow dictate whether that choice remains sustainable. A Solo 401(k) is strictly designed for a business with no full-time employees other than the owner and a spouse. If your growth plan involves hiring team members in Central Ohio next year, that owner-only status will end. Adding eligible staff means your plan becomes subject to broader testing and coverage rules.

A SEP IRA accommodates employees, but with a strict rule: whatever contribution percentage you choose for yourself must also be contributed for every eligible employee. If you contribute fifteen percent of your own compensation, you must contribute fifteen percent for your team. The Department of Labor guidance on choosing a retirement solution outlines how employer contributions must remain uniform across all qualifying staff. Knowing your hiring timeline keeps an attractive deduction today from becoming an unsustainable overhead burden tomorrow.

Connecting Retirement to Business Structure and Cash

Retirement contributions do not happen in isolation from other financial decisions. How you fund a plan interacts directly with how much you pay yourself from your business, whether you operate as an S corporation or a limited liability company, and other year-end priorities like buying equipment before year-end.

For an owner of an S corporation, retirement contributions are calculated from W-2 wages, not total business profit. If your reasonable salary is set conservatively, your allowable employer contribution percentage applies only to that wage figure. Furthermore, making deductible retirement contributions reduces your taxable income, which can influence other calculations such as the qualified business income deduction. When decisions are made in separate silos, owners often discover why owners owe unexpected taxes at filing time.

At Mantle™, we believe wealth is a tool rather than a final destination, meant to help owners build intentionally and do good with their money. That intention requires seeing how every financial decision fits together. In The Mantle Blueprint™, we map an owner's entire financial world on a single page, showing how tax strategy, bookkeeping, cash flow, and business entity choices interact. Clients review prior returns, entity documents, and a concise questionnaire with Hava Laudon, an Enrolled Agent, to identify which opportunities actually fit before locking in irreversible year-end decisions. Seeing what a one-page map of your financial world actually shows gives you clarity before you sign plan documents. When you are working with an Enrolled Agent, your retirement strategy connects seamlessly with your long-term vision.

FAQ

What is the downside of a solo 401k?

The main drawback is the administrative requirement as the plan grows. If account assets reach $250,000 at year-end, the plan generally must file an annual Form 5500-EZ with the IRS.

Can you do a SEP IRA and a solo 401k?

A business owner cannot fund both plans for the same business in the same tax year. While an owner with two distinct businesses might maintain separate plans, aggregate contribution limits across all plans still apply.

Can I convert my SEP IRA to a Solo 401k?

Yes, an existing Simplified Employee Pension balance can typically be rolled into a Solo 401(k) plan if the new plan document permits incoming rollovers. This allows an owner to consolidate retirement balances into a single plan structure.

What is the 3 of 5 rule for SEP IRAs?

The rule requires an employer to include any employee who is at least 21 years old and has worked for the business in at least three of the prior five calendar years. When eligible employees participate, the employer must make proportional contributions for them.