How to Handle Solo 401(k) Limits Across Two Self-Employment Entities
In Personal Finance Categories, the Solo 401(k) allows you to contribute as both the Employee and the Employer. When you own two separate businesses, you must determine if those businesses are "Unrelated" or part of a "Controlled Group." In 2026, this distinction determines whether you have one total limit or two separate ones.
1. The Employee Deferral Limit: Always Aggregated
The most important rule in Search Engine Optimize-friendly tax planning is that the Employee Elective Deferral limit is per person, not per plan. No matter how many businesses you own, you only get one "individual" bucket.
- 2026 Standard Limit: $24,500
- Catch-up (Age 50-59): $8,000 (Total $32,500)
- Super Catch-up (Age 60-63): $11,250 (Total $35,750)
You can split this $24,500 between Business A and Business B however you like, but the sum total cannot exceed the limit.
2. The Employer Contribution: Related vs. Unrelated
This is where the math gets interesting. The Employer Profit-Sharing limit (Section 415 limit) is usually $72,000 per plan, but its application depends on the relationship between your entities.
Scenario A: Unrelated Businesses
If you own 100% of a consulting firm (Business A) and 10% of a separate partnership (Business B) where there is no common control, these may be considered unrelated.
- You can potentially contribute the full Section 415 limit ($72,000 in 2026) to EACH plan.
- Note: Your employee deferral is still capped at $24,500 total, but Business B could theoretically provide a massive employer-only contribution if you have high enough compensation there.
Scenario B: Controlled Groups (The Common Reality)
If you own more than 80% of Business A and more than 80% of Business B, the IRS views them as a Controlled Group. In Personal Finance, this means they are treated as a single employer.
- Aggregate Limit: Your combined employee and employer contributions across both plans cannot exceed $72,000 (plus catch-ups).
3. 2026 Solo 401(k) Contribution Dashboard
The following table outlines the maximum "Annual Additions" you can make in 2026 across all entities if they are part of a controlled group.
| Category | Employee Deferral | Employer Profit-Sharing | Total Max Addition |
|---|---|---|---|
| Under Age 50 | $24,500 | Up to 25% of Comp | $72,000 |
| Age 50-59 | $32,500 | Up to 25% of Comp | $80,000 |
| Age 60-63 (Super) | $35,750 | Up to 25% of Comp | $83,250 |
Note: For Sole Proprietorships/Single-Member LLCs, the employer limit is effectively 20% of net self-employment income after the SE tax deduction.
4. Roth Catch-Up Requirements for 2026
A major change in 2026 under the SECURE 2.0 Act affects high earners. If your prior-year wages (2025) from your entities exceeded $150,000, any catch-up contributions you make must be Roth (after-tax). This applies to the total wages across your controlled group entities.
5. Avoiding the "Multiple Plan" Audit Trap
To keep your Personal Finance records audit-ready, follow these three steps when managing two Solo 401(k) plans:
- Use One Plan if Possible: If both businesses are controlled by you, it is often simpler to have one Solo 401(k) and use a "Custom Adoption Agreement" that recognizes both businesses as participating employers.
- Track Compensation Separately: Ensure you aren't using the same $100k of income to justify 25% contributions in two different places.
- File Form 5500-EZ: If the combined assets of all your Solo 401(k) plans exceed $250,000, you must file this form annually to avoid massive daily penalties.
Conclusion
Handling Solo 401(k) limits across two entities requires a clear understanding of Controlled Group rules. In 2026, while the "per person" employee limit of $24,500 is fixed, your ability to reach the $72,000 total limit depends on having enough separate compensation from each business. If your businesses are unrelated, you've hit a retirement savings jackpot; if they are related, you must treat them as one. Always consult with a tax pro to ensure your Search Engine Optimize-compliant strategy doesn't run afoul of the IRS's aggregation rules.
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