Form 5500-EZ vs Form 5500-SF for a Solo 401(k)
How a one-participant plan should think about the two short Form 5500-series lanes before preparing a packet.
Summary
Form 5500-EZ is the IRS annual return for a one-participant (owner/partner + spouse) plan; Form 5500-SF is a DOL/IRS short form for eligible small plans with non-owner participants and is always electronic via EFAST2. Example: an LLC with only the owner and his spouse covered files 5500-EZ, even after the $250,000 trigger; the same LLC after hiring one eligible employee leaves the EZ lane entirely. Solo 5500 Desk is scoped to Form 5500-EZ only.
Supported product lane: Form 5500-EZ for simple one-participant Solo 401(k) plans.
| 5500-EZ | One-participant or foreign plan returnOwner-only Solo 401(k) cases usually start here. |
|---|---|
| 5500-SF | Short Form 5500-series returnSeparate electronic DOL/IRS lane; outside this MVP. |
| Product boundary | 5500-EZ packet onlyNo Form 5500-SF transmission, review, or plan-administration service. |
Start with the official form purpose
The IRS title for Form 5500-EZ identifies the one-participant plan lane. That is the narrow use case this product supports: an owner-only or partner-only defined contribution Solo 401(k), with spouse coverage only where allowed, and no common-law employee plan issues.
Why the distinction matters
A filing workflow is not just a PDF. It affects the official system used, the form fields, the signing path, and the software provider boundary. Treating Form 5500-EZ and Form 5500-SF as interchangeable creates avoidable filing risk.
When to stop
Stop if you are unsure whether the plan is one-participant, if the plan has non-owner employees, if you need an amended or late filing, or if a prior filing used a different 5500-series form. That is a review question for official instructions or a qualified plan professional.
Common questions
Can a Solo 401(k) use Form 5500-SF instead?
Some one-participant plans may be able to file electronically using Form 5500-SF, but Solo 5500 Desk is not a 5500-SF workflow. It is designed around the Form 5500-EZ packet lane.
Why does the product not choose between forms for me?
Choosing a filing lane can depend on facts outside the simple packet, including plan type, filing method, and official instructions for the year. The app flags the supported lane and hard-stops unsupported cases.
Is Form 5500-SF paper-filed?
Form 5500-SF is an electronic Form 5500-series filing. Form 5500-EZ can be paper-filed only when paper is still permitted for the sponsor.
Related guides
Do I need to file Form 5500-EZ for my Solo 401(k)?
The direct filing test for one-participant plans: asset threshold, final year, deadline, and filing method.
Solo 401(k) $250,000 threshold for Form 5500-EZ
How the IRS $250,000 one-participant plan asset threshold works for Solo 401(k) Form 5500-EZ filing.
Final Solo 401(k) plan year: when Form 5500-EZ still matters
Why a terminating one-participant plan can still have a Form 5500-EZ filing even below the normal asset threshold.
Official sources for this guide
Last reviewed: .