What Is Form 5558?

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Published By: WebHR Team

Updated On: 2026-05-29 05:49:20

What Is Form 5558?

What is Form 5558?

Form 5558 is an IRS form officially called the "Application for Extension of Time to File Certain Employee Plan Returns".

That is, it is a form designed specifically for employers and plan administrators who need extra time to file certain employee benefit plan returns.

In simple words, if you are responsible for filing annual employee plan returns and you cannot meet the original deadline, Form 5558 is what gives you that breathing room.

It extends your filing deadline so you can submit accurate and complete information without rushing.

It is important to understand one thing clearly. Form 5558 only extends the time to file the return.

That is, it does not give you extra time to pay any taxes that are owed. All tax payments must still be made by the original due date to avoid interest and penalties.

Filing Form 5558 on time can help employers avoid costly penalties and keep their employee benefit plan records in good standing with the IRS.

Who Must File Form 5558?

Employers, plan administrators, and other authorized representatives are responsible for filing Form 5558 when they need additional time to submit the relevant employee plan returns.

Both single-employer plans and multiple-employer plans may need to file, but they follow slightly different rules.

Single-Employer Plans

For single-employer plans, one Form 5558 can cover multiple plans as long as they all share the same plan year end date.

That makes the process more manageable for employers running more than one plan.

Multiple-Employer Plans

For multiple-employer plans or plans with unique circumstances, each plan may require its own separate Form 5558 to secure the extension.

That is something plan administrators need to keep in mind to avoid any gaps in coverage.

Forms Covered by Form 5558

Form 5558 applies to several employee benefit plan returns. Knowing which forms are covered helps you determine whether you actually need to file this extension.

Form 5500

This is the annual return and report for employee benefit plans. It is one of the most commonly filed forms that Form 5558 covers.

Form 5500-EZ

This version is used specifically for one-participant retirement plans, like those set up by self-employed individuals or sole proprietors.

Form 8955-SSA

This form reports separated participants who still have deferred vested benefits under the plan.

Form 5330

This is the return for excise taxes related to employee benefit plans. The extension rules for Form 5330 are slightly different, which we will cover in detail below.

Filing Form 5558 ensures the deadline for all of these forms is extended, giving employers the extra time they need to gather information and file accurately.

Filing Deadlines and Extension Periods

Understanding the deadlines is one of the most important parts of working with Form 5558.

Standard Deadline for Forms 5500, 5500-EZ, and 8955-SSA

The standard filing deadline for these forms is the last day of the seventh month following the plan year-end. Filing Form 5558 grants an automatic 2½-month extension for these forms.

Extension for Form 5330

For Form 5330, the IRS may grant an extension of up to six months when Form 5558 is filed.

However, remember that this extension applies to filing only, not to paying the excise taxes owed.

Special Circumstances

In certain situations, like natural disasters or federally declared emergencies, the IRS may offer additional flexibility around deadlines.

It is always worth checking IRS announcements if your area has been affected by such events.

Automatic Extension Option

If the employer's tax year matches the plan year, the federal income tax return extension may automatically apply to Form 5500 or Form 5500-EZ.

However, this only works if the extension is properly documented and a copy is attached to the annual return.

Step-by-Step Instructions to Complete Form 5558

Form 5558 is divided into three parts. Here is a simple breakdown of what each part requires.

Part I – Identification

This section asks for basic identifying information. That includes the employer or plan sponsor's name, address, plan name, plan number, employer identification number or EIN, and the plan year end date.

If you do not have an EIN at the time of filing, you will need to complete Form SS-4 and attach it to your submission.

Part II – Extension for Forms 5500, 5500-EZ, or 8955-SSA

This part is where you request the extension for these specific forms. You will need to specify the desired extension date.

Keep in mind that the requested date cannot go beyond the 15th day of the third month following the original Form 5500 due date.

Part III – Extension for Form 5330

If you are requesting an extension for Form 5330, this is the section you use. It requires you to specify the excise tax code, provide estimated tax amounts, and explain why the extension is necessary.

Accuracy and consistency across all three parts are essential. Any errors or missing information can result in the extension being denied.

Can Form 5558 Be Filed Electronically?

This is one of the most frequently asked questions about Form 5558, and the answer is straightforward.

No, Form 5558 cannot be filed electronically. The IRS only accepts paper submissions for this form. There is no e-filing option available at this time.

That means you will need to print the completed form and mail it to the IRS.

This is important to keep in mind because many filers are used to submitting tax-related documents online and may assume the same applies here.

Since paper filing is the only accepted method, giving yourself enough lead time before the deadline is especially important.

Mailing takes time, and if your form arrives after the original due date, the extension will not be valid.

Where Do I Mail Form 5558?

Another common question people ask is where to mail Form 5558. Once your form is completed, it must be mailed to the IRS office in Ogden, Utah. That is the only IRS location that processes Form 5558 submissions.

Accepted Delivery Methods

You can use any of the following to send your form:

• United States Postal Service (USPS)
• FedEx
• UPS
• DHL

All of these are accepted by the IRS as approved delivery services for this form.

Use Certified or Tracked Mail

It is strongly recommended that you send Form 5558 using certified mail or a tracking-confirmed delivery service.

That way, you have proof of the date you mailed the form. This is especially important if the IRS ever questions whether your submission arrived before the original filing deadline.

Deadline for Mailing

Remember, the form must be received by the IRS on or before the original filing deadline for the extension to be valid.

Submitting late, even by one day, can result in the extension being denied and penalties being applied.

Payment Instructions for Form 5330

While Form 5558 extends the deadline for filing Form 5330, it does not extend the deadline for paying the related taxes. That is a distinction that many filers overlook.

How to Make Payment

Payments must be made by check or money order made payable to the United States Treasury. No other payment methods are accepted alongside this form.

What to Include on the Payment

When sending your payment, make sure to include the following details:

• Employer's name
• EIN or SSN
• Plan number
• Tax year
• Form 5330 section number

Including all of this information ensures your payment is properly applied to the correct account.

Who Must Sign Form 5558

Form 5558 must be signed by a qualified individual. That includes the employer, plan sponsor, plan administrator, attorney, accountant authorized to practice before the IRS, or a person with power of attorney. An unsigned form can be rejected outright.

Once the IRS processes the form, they will notify the filer by mail whether the extension has been granted.

Common Errors and How to Avoid Them

Even small mistakes on Form 5558 can lead to delays, penalties, or outright denial of the extension. Here are the most common errors filers make and how to avoid them.

Filing After the Original Due Date

This is the most critical mistake. If Form 5558 is submitted after the original deadline, the extension will not be granted. Always submit well in advance.

Leaving Critical Fields Blank

Missing information like the EIN, plan year end date, or plan number can cause the form to be rejected. Double-check every field before mailing.

Attempting Electronic Submission

As mentioned earlier, Form 5558 cannot be filed electronically. Trying to submit it online will not work and could result in missing your deadline entirely.

Not Attaching the Extension Copy

Failing to attach a copy of the approved extension to the applicable Form 5500 or Form 5500-EZ is another common oversight. That copy is what documents your compliance.

No Proof of Mailing

Always retain proof that you mailed the form on time. Without it, you have no way to dispute an IRS claim that the form was received late.

Exceptions and Automatic Extensions

In some situations, you may not need to file Form 5558 at all.

When Tax Years Coincide

If your employer's tax year and the plan year are the same, an extension of the federal income tax return may automatically apply to your Form 5500 or Form 5500-EZ filings.

In that case, simply attach a copy of the federal extension to your annual return to document compliance.

Multi-Plan Filings

If a single employer has multiple plans that all share the same plan year-end date, one Form 5558 can cover all of them. That simplifies the filing process significantly.

When the Automatic Extension Ends Early

If the automatic extension expires before the plan's actual filing due date, a separate Form 5558 must still be submitted to cover the remaining period. That is an easy detail to miss, so it is worth marking on your calendar.

Penalties and Processing Times

How Long Does the IRS Take to Process Form 5558?

The IRS typically takes six to eight weeks to process Form 5558. Once approved, the IRS will confirm the new filing deadline in writing.

What Are the Penalties for Not Filing?

Failing to file Form 5558 on time or submitting incorrect information can result in penalties. For Form 5330 specifically, penalties can reach $25 per day, with a maximum of $15,000 per return.

That adds up quickly, which is why timely and accurate filing matters so much.

Interest on Unpaid Taxes

It is also worth noting that filing an extension does not stop interest from accruing on any unpaid taxes.

Interest continues to build from the original payment due date, regardless of whether an extension has been granted.

Best Practices for Filing Form 5558

Following a few simple best practices can make the entire process smoother and reduce the risk of errors or penalties.

Submit Early

Do not wait until the last minute. Submitting Form 5558 well before the original due date gives you time to fix any issues and ensures the form arrives on time.

Keep Accurate Records

Maintain copies of all submitted forms, payment confirmations, and mailing receipts. These records are essential if the IRS ever audits your filing or questions your submission.

Double-Check All Information

Before mailing, review all identifying information including the plan number, EIN, and plan year end date. Even a small typo can cause delays or rejection.

Include Estimated Tax Payments When Required

If you owe taxes related to Form 5330, make sure to include the estimated payment with your submission. Filing the extension without the payment does not protect you from interest charges.

Use Qualified Signatories

Make sure the form is signed by an authorized individual. An unsigned or improperly signed form can be rejected without processing.

Conclusion

Form 5558 is an essential tool for employers and plan administrators who need additional time to file employee benefit plan returns accurately.

Understanding what Form 5558 is, knowing that it cannot be filed electronically, and being clear on where to mail Form 5558 are three of the most important things any filer should know before getting started.

By filing on time, paying any taxes owed by the original due date, avoiding common errors, and following best practices, you can stay compliant with IRS requirements and protect your organization from unnecessary penalties and interest charges.

With the right preparation, filing Form 5558 is a straightforward process that gives you the time you need to get things right.