Retirement Plans for Self-Employed Tax Preparers: SEP IRA, Solo 401(k), and SIMPLE IRA Guide

An independent tax preparer filing Schedule C is running a business. The deductions available to that business include a category that most solo practitioners underuse: qualified retirement plan contributions. A SEP IRA, a Solo 401(k), or a SIMPLE IRA can shelter a meaningful portion of net profit from both income tax and self-employment tax each year. For a preparer who spends the filing season advising clients on retirement planning, not having a plan for their own practice is a gap worth closing.

This guide is written specifically for independent tax preparers who file Schedule C and are not employees of a tax firm. It covers the three plans most relevant to solo practices (SEP IRA, Solo 401(k), and SIMPLE IRA), how each plan affects self-employment tax and the QBI deduction, the 2026 contribution limit landscape, and the practice-stage decisions that determine which plan fits which situation. The guide also covers SECURE 2.0 provisions that apply to self-employed preparers, establishment and contribution deadlines, and the reporting requirements that come with each plan type.

All contribution limit figures in this guide are approximations hedged for annual IRS adjustment. Verify current contribution limits at IRS.gov/retirement-plans before contributing or advising clients. IRS limits are adjusted annually by cost-of-living Rev. Proc. and the figures in effect at the time you read this guide may differ from the amounts cited here. This guide is informational and does not constitute legal or tax advice. Plan selection involves individual facts; consult a qualified CPA or tax advisor for specific planning decisions.

Why Your Retirement Plan Matters: The Self-Employment Tax Offset

For a Schedule C filer, a qualified retirement plan contribution does something an ordinary business expense does not: it reduces tax at two levels simultaneously. Understanding this double benefit is the starting point for evaluating any retirement plan decision.

How the deduction flows for a Schedule C preparer

A self-employed tax preparer pays self-employment tax on net profit from the practice. SE tax applies at a combined rate (Social Security and Medicare components) on net self-employment income up to the Social Security wage base, and at the Medicare rate above it. Net profit is the figure from Schedule C after ordinary and necessary business deductions. A retirement plan contribution made under the SEP IRA or Solo 401(k) rules (the employer portion) is deducted on Form 1040 as an adjustment to income, not on Schedule C itself. This means it does not directly reduce SE tax. However, the contribution calculation is based on net self-employment income after the deduction for one-half of SE tax, and the resulting deduction reduces adjusted gross income, which in turn reduces the income available for the additional Medicare tax calculation at higher income levels.

The practical result for most solo preparers: every dollar contributed to a qualified retirement plan reduces federal income tax by the preparer's marginal rate. For a preparer in the 22 percent bracket, a $10,000 SEP contribution produces approximately $2,200 in federal income tax savings. If the preparer is subject to the additional Medicare tax, the savings increase modestly. The point is not the precise arithmetic; it is that a retirement plan contribution is one of the highest-value deductions available to a Schedule C filer because it reduces taxable income without reducing the gross revenue that defines the practice.

The interaction with self-employment tax

Retirement plan contributions for self-employed individuals are calculated using a net self-employment compensation figure that already accounts for the deduction for one-half of SE tax. This creates a circular calculation that the IRS resolves with a fixed formula (the effective contribution rate for a SEP IRA works out to approximately 18.587 percent of net profit when restated as a percent of gross net profit, not the headline 25 percent). The key takeaway for a practitioner: the SEP IRA and Solo 401(k) employer contribution both feed off a net income figure reduced by the SE tax deduction. The practical effect is that higher SE tax reduces the contribution base, which slightly reduces the maximum retirement plan contribution available.

For a Solo 401(k), there is an additional component: the employee deferral. The employee deferral is not subject to the net self-employment income calculation in the same way. The employee deferral can be contributed up to 100 percent of net self-employment compensation (up to the annual deferral limit), which gives a Solo 401(k) participant the ability to shelter a much larger proportion of a lower-income year's profit than a SEP IRA would allow. This deferral difference is the central reason a higher-income solo preparer should evaluate the Solo 401(k) rather than defaulting to the SEP IRA.

Why starting a plan early in the practice lifecycle matters

A preparer who establishes a plan in the first profitable year captures the deduction during the years when startup costs and practice-building investments are competing for every dollar of net income. The tax savings from the retirement contribution help fund the plan itself. Waiting until income is higher before starting a plan means passing up years of compounding on tax-deferred contributions. For a preparer just starting out, even a small SEP IRA contribution in a lean year establishes the habit and the plan structure that scales as the practice grows. See the guide to starting a tax preparation business for the full practice setup checklist, including initial business structure decisions that affect retirement plan options.

The Three Core Plans for an Independent Tax Practice

Independent tax preparers on Schedule C have access to three plan types that are practical for a solo or small practice: the SEP IRA, the Solo 401(k), and the SIMPLE IRA. Each has a distinct contribution structure, deadline profile, and administrative requirement. This section gives a high-level orientation before the section-by-section deep dives that follow.

All limit figures are approximate and subject to annual IRS cost-of-living adjustment. Verify current limits at IRS.gov/retirement-plans before contributing.

SEP IRA: Limits, Flexibility, and When It Wins

The SEP IRA is the default starting point for most independent tax preparers. Its structural simplicity is its primary advantage: no plan document beyond the IRS model agreement (Form 5305-SEP or a financial institution's equivalent), no annual government filing requirement, and a contribution deadline tied to the extended due date of the tax return rather than the end of the calendar year.

How the SEP IRA contribution is calculated

The SEP IRA contribution limit for a self-employed individual is the lesser of 25 percent of net self-employment compensation or the annual dollar limit (approximately $69,000 for 2026; verify at IRS.gov/retirement-plans). Net self-employment compensation for this purpose is net profit from Schedule C, reduced by the deduction for one-half of self-employment tax. Because the calculation works off post-SE-tax-deduction income, the effective rate as a percentage of raw Schedule C net profit is approximately 18.6 percent rather than 25 percent. Most major custodians and tax preparation software calculate this automatically, but a preparer operating their own practice should understand what is driving the number.

The contribution is not mandatory each year. A SEP IRA allows the practitioner to contribute a different amount year to year, including contributing nothing in a loss year. This flexibility suits a tax preparation practice where net profit fluctuates with client volume and seasonal concentration. There is no penalty for skipping a year, and no minimum contribution is required.

The deadline advantage: extended due date funding

A SEP IRA can be established and funded as late as the extended due date of the tax return for the year in which the contribution will be deducted. For a calendar-year Schedule C filer who files for an extension, this typically means the plan can be opened and the contribution made as late as October 15 of the following year. This is the longest funding window of any common self-employed retirement plan. A preparer who files their own extension has until the October deadline to decide the exact contribution amount after final income figures are settled. This removes the December 31 pressure that the Solo 401(k) imposes.

When the SEP IRA wins

The SEP IRA is the right choice for a solo preparer in the following circumstances: the practice has no W-2 employees (other than a spouse), the preparer wants to defer the contribution decision until after the return is prepared and income is finalized, the preparer's net income is high enough that the percentage-based limit produces a large contribution without needing the deferral layer, and the preparer does not want to manage plan documents or track annual filing requirements. For a higher-income solo preparer who has already maximized the percentage-based contribution and wants to shelter more income through a separate deferral layer, the Solo 401(k) becomes worth evaluating despite its harder deadline.

SEP IRA and employees: the coverage problem

A SEP IRA that covers the owner must also cover all eligible employees under the plan's participation rules. If the practice has W-2 employees who meet the eligibility thresholds, the SEP IRA employer must contribute the same percentage of compensation to the employees' SEP IRAs as the owner contributes to their own. This is not a problem for a pure solo practice, but it is a constraint that changes the plan's cost economics the moment any W-2 employees are hired. At that point, the cost of covering employees through a SEP IRA may make a SIMPLE IRA more attractive, because the SIMPLE IRA's matching requirement is formulaic and predictable rather than percentage-of-contribution-based.

Solo 401(k): Deferral Plus Employer Contribution, Limits, and Plan Documents

The Solo 401(k) is the highest-ceiling retirement plan available to a self-employed tax preparer with no non-spouse employees. Its two-component contribution structure allows a significantly larger total contribution at moderate income levels compared to the SEP IRA alone, because the employee deferral adds to the employer contribution rather than being calculated from it.

How Solo 401(k) contributions are structured

The Solo 401(k) contribution has two separate components. The first is the employee salary deferral: the owner-participant defers a portion of their net self-employment compensation into the plan, up to the annual deferral limit. For 2026, that limit is approximately $23,500 for participants under age 50, and approximately $31,000 for participants aged 50 and older (including standard catch-up contributions). Verify these figures at IRS.gov/retirement-plans, as they are subject to annual adjustment.

The second component is the employer profit-sharing contribution: up to 25 percent of net self-employment compensation (after the SE tax deduction), subject to the overall plan limit. The overall limit for 2026 is expected to be in the range of approximately $70,000 to $72,000, combining both components. Verify the current overall limit at IRS.gov/retirement-plans. At lower income levels, the deferral component is what makes the Solo 401(k) materially better than the SEP IRA. A preparer with $60,000 of net profit, for example, could contribute a much larger percentage of that income through the deferral plus employer contribution structure than through the SEP IRA's percentage-only formula.

The December 31 establishment deadline

The Solo 401(k) plan must be formally established by December 31 of the tax year for which contributions will be made. This is not a funding deadline; it is the plan establishment deadline. The plan document must be signed and the plan legally in existence by December 31. Contributions themselves can generally be funded after December 31 (up to the filing or extended filing deadline for the employer contribution), but the plan must exist before year-end. A preparer who realizes on December 27 that the Solo 401(k) would be more advantageous than the SEP IRA for that year is still in time to establish a plan before the deadline. A preparer who realizes on January 10 of the following year has missed it.

This deadline difference from the SEP IRA is the primary operational constraint of the Solo 401(k). It requires a year-end planning conversation rather than a post-filing decision.

Plan documents: what a Solo 401(k) requires

A Solo 401(k) requires an actual plan document, not just a model IRS form. Most major custodians (Fidelity, Vanguard, Schwab, and others) offer prototype or pre-approved plan documents that satisfy this requirement. The preparer establishes the plan by executing the custodian's adoption agreement, which incorporates the prototype plan document. This process is more involved than establishing a SEP IRA but is still straightforward when done through a custodian with a streamlined process. The plan document establishes the plan's terms, including eligibility, contribution formulas, vesting, and distribution rules.

Roth Solo 401(k) provisions are available through some custodians, allowing the employee deferral component to be designated as Roth (after-tax) rather than traditional (pre-tax). The availability of Roth features depends on the custodian's plan document. A preparer who wants Roth deferral capability should confirm the custodian offers it before establishing the plan.

Form 5500-EZ: when the annual filing requirement kicks in

A Solo 401(k) generally requires filing Form 5500-EZ (Annual Return of a One-Participant Retirement Plan) with the IRS once total plan assets exceed $250,000 at the end of the plan year. Verify the current asset threshold at IRS.gov/retirement-plans, as this threshold is a statutory figure that has not been indexed for inflation but could be updated by legislation. Plans below the threshold are not required to file annually, though a final return (Form 5500-EZ) is required when the plan is terminated. Missing the 5500-EZ filing deadline carries penalties. A preparer accumulating assets in a Solo 401(k) over multiple years should track the plan balance against the threshold as part of their annual tax preparation workflow.

When the Solo 401(k) wins for a Schedule C preparer

The Solo 401(k) is worth the additional setup complexity when: the preparer's income is moderate (the deferral layer adds significant contribution capacity at incomes where the SEP percentage alone would be low), the preparer is age 50 or older and catch-up contributions add meaningful shelter, the preparer specifically wants Roth 401(k) deferral capability, or the preparer's overall planning goal is maximizing annual contribution amounts rather than minimizing administrative steps. The trade-off is the December 31 deadline and the plan document requirement. The Form 5500-EZ filing becomes an ongoing obligation once assets cross the threshold. Preparers comfortable with these requirements and who value the higher contribution capacity should evaluate the Solo 401(k) over the SEP IRA.

SIMPLE IRA: When Employees Change the Calculus

The SIMPLE IRA enters the picture when an independent tax practice grows to include W-2 employees. A Solo 401(k) cannot cover non-spouse employees; the moment a first employee who is not the owner's spouse is hired, the practice needs a plan that accommodates that employee. The SIMPLE IRA is the most common first step for a small practice because it is simpler to administer than a full 401(k) plan while still satisfying the employee coverage requirement.

SIMPLE IRA contribution structure

Employees (including the owner-employee in a SIMPLE IRA context) can defer a portion of their compensation into the SIMPLE IRA, up to the annual employee contribution limit. For 2026, that limit is approximately $16,000; verify the current limit at IRS.gov/retirement-plans. Participants aged 50 and older can make an additional catch-up contribution on top of the base limit; verify the current catch-up amount at IRS.gov. SECURE 2.0 also introduced an enhanced catch-up for ages 60 to 63 for SIMPLE IRAs; verify whether this enhancement is in effect for the year in question at IRS.gov/retirement-plans.

The employer must make matching contributions under one of two formulas: either a dollar-for-dollar match of employee contributions up to 3 percent of compensation (the employer can reduce this to 1 percent in any two of five years under certain conditions), or a non-elective contribution of 2 percent of each eligible employee's compensation regardless of whether the employee contributes. For a practice with a small number of employees, the 3 percent match is typically the most common choice because it only costs the employer money when employees actually contribute, whereas the 2 percent non-elective contribution is mandatory for all eligible employees whether or not they participate.

The October 1 new-plan establishment deadline

A SIMPLE IRA being established for the first time must generally be set up by October 1 of the year it will take effect. A practice that hires its first employee in September needs to begin the SIMPLE IRA setup immediately to meet that deadline. Note that the October 1 deadline applies to the establishment of a new plan. Existing plans making amendments or adding features may operate under different rules. Verify current establishment timing requirements at IRS.gov/retirement-plans before making any plan decisions based on timing.

SIMPLE IRA vs. SEP IRA with employees

A practice that has both a solo owner and W-2 employees could technically maintain a SEP IRA that covers the employees. However, the SEP IRA's coverage rule requires the same contribution percentage for all eligible employees as the owner contributes for themselves. If the owner wants to make a maximum SEP contribution (roughly 18.6 percent of net income), they must contribute that same percentage of each covered employee's compensation. For a practice with even one or two well-compensated staff members, that cost can become prohibitive relative to the SIMPLE IRA's capped matching requirement. This is why most practices transition from a SEP IRA to a SIMPLE IRA as soon as employees are hired, rather than continuing the SEP IRA and bearing the employee contribution cost.

Plan Selection Decision Tree by Practice Stage

Plan selection is not a permanent decision; it is a practice-stage decision. The right plan at practice launch is not necessarily the right plan five years later. This section frames the decision by practice stage.

QBI Deduction Interaction and Coordination Strategy

The Section 199A qualified business income deduction allows eligible self-employed individuals and pass-through entity owners to deduct up to 20 percent of qualified business income. For a Schedule C tax preparer, the starting point for QBI is generally the net profit from Schedule C (subject to the specific QBI calculation rules). Retirement plan contributions interact with this calculation in a way that can reduce the QBI deduction.

How retirement contributions reduce the QBI base

A self-employed retirement plan contribution (the employer portion, deducted as an adjustment to income on Form 1040) reduces adjusted gross income but also reduces the QBI figure available for the Section 199A deduction calculation. Because QBI is derived from the business income net of certain deductions (including the self-employed retirement plan deduction), a larger retirement contribution produces a lower QBI base, which in turn produces a lower Section 199A deduction.

For most preparers who are well below the Section 199A phase-out thresholds (approximately $197,300 for single filers and $394,600 for joint filers for 2026; verify current thresholds), this interaction is not a planning problem. The Section 199A deduction at those income levels is generally available without the wage-and-capital limitations, and reducing the QBI base by retirement contributions reduces the deduction but also reduces the income on which the deduction is calculated. The net tax effect is still strongly positive in most cases.

Where the interaction becomes a planning question

The QBI-retirement interaction becomes a more significant planning question when the preparer is near the income thresholds where the Section 199A deduction begins to phase out, or where the W-2 wage limitation begins to apply. At those income levels, a retirement contribution that reduces QBI below a threshold could affect which limitation applies to the deduction, and the relationship between the contribution benefit (income tax savings from the deduction) and the QBI cost (reduction in the 20 percent deduction) requires careful modeling.

Tax preparation services are classified as a Specified Service Trade or Business (SSTB) under Section 199A for preparers with income above the phase-out thresholds. This SSTB classification means the Section 199A deduction may be fully disallowed above a certain income level. For a preparer approaching or above the SSTB phase-out range, the QBI deduction may already be limited or eliminated regardless of retirement contributions. In that scenario, the retirement contribution's value is purely its income tax savings; the QBI interaction is not a significant factor because the QBI deduction is already constrained.

The interaction is most worth modeling for a preparer whose income sits in the phase-out range, where both the retirement contribution deduction and the QBI deduction are partially in play simultaneously. For the full Section 199A analysis as it applies to independent tax preparers, see the QBI deduction guide for self-employed tax preparers. This is a planning area where the right answer depends on the preparer's complete income picture, filing status, and whether other income sources affect the threshold calculations. Consult a CPA or tax advisor before optimizing retirement contributions around the QBI interaction.

SECURE 2.0 Changes Affecting Self-Employed Tax Preparers

The SECURE 2.0 Act of 2022 made several changes to retirement plan rules that affect self-employed individuals. The changes most relevant to an independent tax preparer on Schedule C involve catch-up contribution enhancements and a new Roth catch-up requirement for high earners.

Enhanced catch-up contributions for ages 60 to 63

SECURE 2.0 created a new super catch-up contribution for 401(k) plan participants aged 60, 61, 62, and 63. This enhanced catch-up amount is the greater of $10,000 or 150 percent of the standard catch-up contribution limit. For 2026, the enhanced catch-up for Solo 401(k) participants in this age range is expected to be approximately $11,250, but verify the current amount at IRS.gov/retirement-plans, as this figure is subject to annual cost-of-living adjustment and may differ at the time you read this guide. This enhancement applies only to 401(k)-type plans (including Solo 401(k)s); it does not apply to SEP IRAs or SIMPLE IRAs, which have their own separate catch-up rules.

For a Solo 401(k) participant aged 60 to 63, the super catch-up represents a meaningful additional tax deferral opportunity during the peak savings window before retirement. A preparer in this age range who has been using a SEP IRA should specifically evaluate whether switching to a Solo 401(k) before December 31 makes sense given the enhanced catch-up capacity, because the SEP IRA does not offer this benefit.

Roth catch-up requirement for high earners: verify effective date before advising

SECURE 2.0 included a provision requiring that catch-up contributions made by plan participants whose FICA wages from the employer exceeded a threshold in the prior year must be designated as Roth (after-tax) rather than pre-tax. For a Solo 401(k) participant, this would mean that if the participant's self-employment compensation exceeded the relevant threshold, catch-up contributions would need to go into the Roth account. IRS Notice 2023-75 delayed the implementation of this requirement while the IRS worked through administrative and plan document questions. Verify the current effective date at IRS.gov before making any plan design or contribution allocation decisions related to the Roth catch-up rule.

SEP Roth IRA: a new option from SECURE 2.0

SECURE 2.0 also authorized SEP Roth IRAs and SIMPLE Roth IRAs, allowing employer contributions to these plan types to be designated as Roth. As of the date of this guide, not all custodians have implemented these new Roth options for SEP and SIMPLE IRAs, and the operational guidance from the IRS has been developing. If a self-employed preparer is interested in Roth contributions within a SEP or SIMPLE structure, they should verify with their custodian whether the option is available and confirm the current IRS guidance on implementation. The underlying statutory authority exists; availability in practice depends on custodian implementation and IRS procedural guidance.

Other SECURE 2.0 provisions to be aware of

SECURE 2.0 included numerous other provisions, some of which affect self-employed individuals: changes to Required Minimum Distribution ages (increased to 73 for those who turn 73 after December 31, 2022, and further to 75 for those who turn 74 after December 31, 2032, pending confirmation of the full statutory schedule at IRS.gov), adjustments to penalty structures, and starter 401(k) provisions for small employers. For a comprehensive list of SECURE 2.0 provisions and their effective dates, consult IRS.gov/retirement-plans and IRS Notice 2024-2 (the IRS's initial SECURE 2.0 guidance notice). The retirement landscape post-SECURE 2.0 continues to develop through additional IRS guidance.

See our OBBBA Practice Guide 2026 for how recently enacted legislation may affect the QBI deduction, individual return changes, and the broader 2026 planning picture for self-employed preparers.

Establishing a Plan: Deadlines, Custodian Selection, and Plan Documents

Getting the establishment deadline right is the most operationally important part of setting up any self-employed retirement plan. Missing the applicable deadline for a given plan type means missing the deduction for that tax year.

Deadline summary

• SEP IRA: Can be established and funded up to the extended due date of the tax return for the contribution year (typically October 15 for calendar-year filers who filed for an extension). No separate plan establishment step is required before that date; the plan is established when the SEP IRA agreement is executed and the first contribution is made. Verify the current IRS deadline rules at IRS.gov/retirement-plans.
• Solo 401(k): The plan must be established (plan document signed) by December 31 of the tax year for which contributions will be made. The employer profit-sharing contribution can be funded after December 31, up to the tax filing deadline or extended deadline. The employee deferral contribution must generally be made or irrevocably elected by December 31. Verify current rules at IRS.gov/retirement-plans.
• SIMPLE IRA (new plan): Must generally be established by October 1 of the year the plan will take effect. This applies to a brand-new plan being established for the first time. Existing plans making changes may operate under different timing rules. Verify the applicable deadline for your specific situation at IRS.gov/retirement-plans.

Custodian selection

A custodian must hold the retirement plan assets. Major brokerage and investment firms (Fidelity, Vanguard, Schwab, T. Rowe Price, and others) offer SEP IRAs, Solo 401(k)s, and SIMPLE IRAs. The selection criteria that matter most for an independent tax preparer are: whether the custodian offers the plan type needed, whether the custodian's plan document (for Solo 401(k)) includes the features wanted (Roth option, loan option if desired, investment flexibility), and the custodian's process for establishing the plan before year-end deadlines. For a December 31 Solo 401(k) establishment, the preparer should contact the custodian well before December to confirm how the establishment process works and how long it takes. Some custodians have deadline cutoffs for new Solo 401(k) applications well before December 31 due to processing time.

Plan document requirements

The SEP IRA uses Form 5305-SEP (IRS model SEP agreement) or an equivalent financial institution form. This is a two-page document; no IRS submission is required to establish it. The SIMPLE IRA uses Form 5304-SIMPLE (if each employee chooses their own financial institution) or Form 5305-SIMPLE (if a single financial institution is designated). These are also IRS model forms; no IRS submission is required.

The Solo 401(k) requires an actual plan document, which is typically the custodian's prototype or pre-approved 401(k) plan document incorporated by reference in an adoption agreement. The preparer signs the adoption agreement, which legally establishes the plan. The plan document governs contribution formulas, eligibility, vesting, and distributions. Keep the signed adoption agreement and plan document in the practice's permanent records; they are the evidence of plan establishment in the event of an IRS audit of retirement deductions.

No ERISA annual filing for SEP and SIMPLE below threshold

SEP IRAs and SIMPLE IRAs held at financial institutions generally are not subject to ERISA annual reporting requirements (Form 5500 series) as long as they meet certain conditions, including that they are maintained through IRAs at financial institutions and that plan assets do not require special handling. The Solo 401(k) is subject to Form 5500-EZ once plan assets exceed the applicable threshold (currently $250,000; verify at IRS.gov/retirement-plans). This is a significant administrative difference and one of the reasons many solo preparers who do not expect to accumulate assets above the threshold in the near term prefer the SEP IRA's simpler compliance profile.

Reporting Requirements: Form 5500-EZ and How Contributions Flow to Schedule C

Understanding where retirement plan deductions appear on the tax return and what annual filing obligations apply is essential for a Schedule C preparer who is also managing their own practice finances.

Where the deduction appears: not on Schedule C

Self-employed retirement plan contributions (SEP IRA, Solo 401(k) employer portion, and SIMPLE IRA employer contributions made by the self-employed individual) are deducted as adjustments to income on Form 1040, Schedule 1, Part II, not on Schedule C. This is important for two reasons. First, it means the contribution does not reduce net profit on Schedule C (and therefore does not reduce self-employment tax). Second, it means the deduction appears in the calculation of adjusted gross income rather than in the Schedule C income. The contribution reduces taxable income but the SE tax base remains the Schedule C net profit before the retirement contribution adjustment.

The Solo 401(k) employee deferral is also deducted on Schedule 1 as a self-employed retirement plan deduction. The total deduction (deferral plus employer contribution) flows through as a single above-the-line adjustment that reduces AGI.

Form SE interaction

Schedule SE computes self-employment tax on net profit from Schedule C. The retirement plan deduction does not reduce the Schedule SE calculation directly. However, the deduction for one-half of self-employment tax (which reduces the contribution base for retirement plan purposes) is itself computed on Schedule SE. The interdependency between SE tax and the retirement plan contribution ceiling is resolved by the IRS's prescribed calculation methodology for self-employed individuals, which all major tax preparation software handles automatically.

For a preparer manually computing their own return or reviewing a client's return, the key check is that the retirement plan deduction on Schedule 1 does not exceed the computed maximum for the plan type, and that the maximum was computed off the net self-employment compensation figure (net Schedule C profit minus one-half SE tax, not net profit directly).

Form 5500-EZ: Solo 401(k) annual reporting obligation

Form 5500-EZ is the Annual Return of a One-Participant (Owner and Their Spouses) Retirement Plan. It is required for Solo 401(k) plans once total plan assets exceed $250,000 at the end of the plan year. Verify the current threshold at IRS.gov/retirement-plans; this is a statutory dollar figure and is subject to legislative change.

The Form 5500-EZ filing deadline is the last day of the seventh month after the plan year ends (July 31 for calendar-year plans), with an automatic 2.5-month extension available on Form 5558. Late filing carries penalties that accrue per day. A preparer who has been accumulating Solo 401(k) assets for several years and has not been tracking the balance against the $250,000 threshold should verify the current plan balance before each filing season. The 5500-EZ is also required as a final return when the plan is terminated, regardless of asset level.

The Form 5500-EZ is filed electronically through the EFAST2 system. It requires basic plan information, a participant count (typically 1 or 2 for an owner-only plan), and the plan's total assets at beginning and end of the year. It is not a complex filing for a one-participant plan, but it must be filed on time. A preparer who runs their own practice but also prepares business returns for clients should not let their own 5500-EZ filing fall through the cracks during the primary filing season.

Home office deduction and retirement plan: a related Schedule C consideration

Independent tax preparers who operate from a dedicated home office can deduct home office expenses on Form 8829, which flows to Schedule C and reduces net profit. A lower Schedule C net profit means a lower retirement plan contribution maximum (since the maximum is based on net SE compensation). Preparers who take both the home office deduction and a retirement plan contribution should understand this interaction: maximizing one deduction slightly reduces the benefit of the other at the margin. For the full home office deduction analysis, see the home office deduction guide for tax preparers, which covers the Form 8829 calculation, the regular-and-exclusive-use requirement, and how the deduction interacts with the overall Schedule C picture.

Practice Growth Checkpoint: When to Upgrade Your Plan

Plan selection should be revisited at specific practice milestones. These are the checkpoints that should trigger a plan review:

Frequently Asked Questions