Solo 401k: What It Is, How It Works, and What to Consider
A solo 401k is a retirement plan designed for a business owner with no full-time employees other than a spouse, depending on plan rules. It may allow self-employed individuals to make both employee and employer contributions, subject to IRS limits and eligibility requirements.
Who a solo 401k may be for
Self-employed individuals, freelancers, and independent contractors
Sole proprietors and single-member LLC owners with net earnings
S-corp owners receiving W-2 income from their business
Married business owners where a spouse works in the business
If you expect to hire employees, plan eligibility rules and design may need to be reviewed with a provider or tax professional.
How contributions generally work
A solo 401k typically includes two contribution types:
Employee contributions
You may defer a portion of compensation up to annual IRS limits. Some plans allow:
Pre-tax contributions, which may reduce current taxable income
Roth contributions, which are made after-tax and may allow tax-free qualified withdrawals
Employer contributions
The business may contribute a percentage of compensation or net earnings depending on entity type. Calculation methods vary based on structure and payroll approach.
Contribution rules can be technical, so many individuals review amounts with a tax professional before funding.
Key features to compare
When evaluating providers, consider:
Roth option availability
Rollover support from prior retirement plans
Loan provisions, if permitted
Investment flexibility and platform access
Plan documents and amendment support
Ongoing administration requirements
Total fees and service structure
Setup and administration basics
Opening a solo 401k generally involves:
Selecting a provider and adopting plan documents
Opening account(s) and setting funding instructions
Tracking employee vs employer contributions separately
Monitoring reporting requirements as assets grow
Some plans may require additional filings once asset thresholds are met.
Common mistakes to avoid
Mixing personal and business funds without clear records
Miscalculating contribution amounts based on compensation
Assuming all plans offer the same features
Missing reporting obligations when plan assets grow
Funding contributions into the wrong category or timing window
Where Compound Wealth fits in
Compound Wealth shares resources focused on tax-aware retirement planning topics that self-employed individuals often review when evaluating options like the solo 401k. Through its website, compoundwealthtax.com, Compound Wealth provides materials that help readers understand how different plan choices may interact with broader tax considerations.
Compound Wealth also outlines how its team approaches guidance so individuals can compare providers and understand what level of support may be appropriate for their situation.
FAQ
What is the main benefit of a solo 401k?
It may allow both employee and employer contributions, which can increase potential annual savings compared to some other retirement plans.
Can I open a solo 401k if I have employees?
Generally, eligibility is limited if you have full-time employees other than a spouse, though rules depend on plan structure.
Are Roth contributions always available?
Not all plans offer Roth options. Availability depends on the provider and plan design.
Do I need a tax professional to set one up?
It is commonly recommended to review contribution calculations and eligibility with a tax professional due to IRS rules and plan complexity.
About Compound Wealth
Compound Wealth works with business owners, entrepreneurs, professionals, and families with increasingly complex financial lives. The firm brings together tax planning, wealth management, client accounting services, and business transition advisory to provide a coordinated planning experience. By evaluating multiple aspects of a client's financial picture together, planning discussions may become more structured and aligned with long-term goals.
