Start with the complete ownership picture

An owner may operate two companies with separate employees, accounts, and accountants while assuming each retirement plan can be analyzed independently. Before establishing a new plan or increasing contributions, disclose all business interests to the plan professional. Include direct and indirect ownership, family interests, management relationships, and services between businesses. The relevant analysis may require more than the name appearing on each company's bank account.

Prepare a simple ownership chart with percentages, entity types, effective dates, and changes during the year. Attach governing documents and identify interests held through other entities or trusts. Do not omit a small or inactive business merely because it has little current revenue. Ask the administrator which facts are relevant and let them determine the applicable treatment. A complete chart is more useful than an owner deciding in advance which businesses probably count.

Add workforce and plan information to the map

List employees, payroll, existing plans, contribution arrangements, and the advisors responsible for each business. Identify people who work for more than one company or provide shared management services. Preserve intercompany agreements and describe how expenses are allocated. Separate payroll systems can hide shared staffing, particularly when one entity employs administrative personnel who support the other.

Publication 560 provides general retirement-plan guidance, but related-business and coverage questions can require specialized analysis. Ask a qualified plan professional to identify any aggregation or affiliated-service issues and the information needed to resolve them. This guide does not conclude that particular businesses must be combined. It describes the factual package required before the owner relies on a separate-plan contribution strategy.

A two-company example that needs review

Suppose an owner operates a consulting company with six employees and owns a significant interest in a separate services business with three employees. The owner wants a new plan in the second business and assumes it can cover only their own compensation. Before the tax projection includes the proposed deduction, the administrator needs the ownership structure, family and indirect interests, service relationships, and both employee groups.

The company should compare possible contribution and administration costs under the professional's conclusions. If the analysis changes eligibility or plan design, the owner needs time to consider the commercial cost and implementation schedule. The example is a prompt for review, not a determination that the two businesses form a particular tax group. A website or separate legal entity does not supply enough facts to decide the issue.

Keep the advisors on one set of assumptions

If different accountants handle the businesses, designate a coordinator for the plan analysis. Share the same ownership chart and workforce information securely with the professionals who need it. Record unresolved questions and the person responsible for answering them. Avoid letting each advisor calculate a favorable result based on a partial view of the owner's interests.

Ask the plan professional to document the conclusions and the circumstances that would require a new review. A purchase, sale, family transfer, or new service arrangement may change the relevant facts. Add those events to the owner's annual planning checklist. The initial analysis should not become a permanent assumption that survives material changes without verification.

Use the reviewed design before committing cash

Once the plan arrangement has been analyzed, obtain contribution estimates, administrative costs, required employee actions, and implementation dates. Coordinate those with the tax advisor's projection and the company's liquidity. Separate tentative owner goals from verified plan results. A large proposed contribution should not reduce estimated payments until the business has a supportable calculation and a feasible funding plan.

Preserve the ownership map, workforce census, advisor conclusions, plan documents, and funding records together. Review the map at least when significant business changes occur. This process cannot replace specialized retirement-plan analysis. It gives that analysis a complete foundation and helps the owner avoid building a tax plan around an incomplete description of their own businesses. The useful result is a coordinated design that fits the actual ownership and workforce.

Ask the owner to sign off on the factual chart before it is circulated. That review can reveal an omitted family interest or recently changed percentage. Keep the signed version and its effective date so later updates can be compared with an understood baseline.

Sources & further reading

Consult the original guidance and its effective dates. These references support the educational discussion; their application depends on the specific facts.

This guide was prepared with AI assistance for AE Tax Advisors. No individual professional review is claimed. Examples are illustrative, not client results. Confirm current law, state treatment, and implementation with a qualified professional. Editorial standards.