The "80-120 rule" allows 401(k) plans with 80–120 participants (with account balances) at the start of a year to file their Form 5500 using the same status (small vs. large) as the previous year. This prevents immediate, costly audits when a plan crosses the 100-participant threshold.
Under current 401(k) audit requirements, an audit is typically triggered when the participant count exceeds 120 as of the first day of the plan year. This is generally January 1, unless your company has specified something else. However, if the plan filed as a small plan the prior year, this may not apply.
The 80-120 participant rule is a provision that gives some flexibility to retirement plans that are hovering around the 100-participant audit threshold. In the context of audits, the "80-120 rule" provides a special exception for plans that fall between 80 and 120 eligible participants.
Fewer 401(k) Plans Will Require A 5500 Audit Starting in 2023. 401(K) plans with over 100 eligible plan participants are considered “large plans” in the eyes of DOL and require an audit to be completed each year with the filing of their 5500. These audits can be costly, often ranging from $8,000 - $30,000 per year.
THE “80-120” PARTICIPANT RULE
Generally, any 401(k) plan that has over 100 eligible participants is considered to be a large plan and will be required to have an annual audit performed by independent auditor.
Not reporting all of your income is an easy-to-avoid red flag that can lead to an audit. Taking excessive business tax deductions and mixing business and personal expenses can lead to an audit. The IRS mostly audits tax returns of those earning more than $200,000 and corporations with more than $10 million in assets.
A taxpayer must get a tax audit done if their business's sales, turnover, or gross receipts are over ₹1 crore, or if their profession's earnings exceed ₹50 lakh in a financial year.
Stay Ahead of the DOL with Smart Planning
For tax year 2025, the most you can contribute to a Roth 401(k), a traditional 401(k), or a combination of the two is $23,500. For 2026, this rises to $24,500 for 2026. Those 50 and older can contribute an additional $7,500 in 2025, and $8,000 in 2026.
Generally speaking, the IRS statute of limitations runs for a period of three years from the date Form 5500 is filed for a given year.
Unreported income
The IRS receives copies of your W-2s and 1099s, and their systems automatically compare this data to the amounts you report on your tax return. A discrepancy, such as a 1099 that isn't reported on your return, could trigger further review.
Every firm has a process for proposals. Understanding audit pricing is crucial for plan sponsors to budget appropriately and avoid unexpected expenses. Generally, single employer 401(k) plan audit fees range from $8,000 to $13,000, and most firms offer flat rate fees.
The Central Board of Direct Taxes (CBDT) has pushed the tax-audit report due date to 10 November 2025 and the ITR filing deadline for audit cases to 10 December 2025, giving businesses and professionals extra time to finish audit work and file returns.
Too many deductions taken are the most common self-employed audit red flags. The IRS will examine whether you are running a legitimate business and making a profit or just making a bit of money from your hobby. Be sure to keep receipts and document all expenses as it can make things a bit ore awkward if you don't.
A successful internal audit function relies on four fundamental pillars, often referred to as the “4 C's”: Competence, Confidentiality, Communication, and Collaboration. These principles guide auditors in delivering meaningful and impactful results. Let's explore each of these elements in detail.
The 7 steps in the audit process generally cover Planning, Risk Assessment, Internal Control Testing, Fieldwork/Evidence Collection, Reporting, and Follow-Up, focusing on a systematic review from initial engagement to ensuring corrective actions are taken for operational improvement. This framework ensures comprehensive evaluation, from understanding the client's business to delivering actionable insights and ensuring accountability for identified issues.
Typically, an audit requirement is triggered when a retirement plan reaches 100 participants with account balances (on the first day of the Plan year), which is considered a “large” plan.
The 401(k) "Rule of 55" allows penalty-free (but still taxable) withdrawals from your current employer's 401(k) if you leave your job in the year you turn age 55 (or 50 for certain public safety workers), bypassing the usual 10% early withdrawal penalty for distributions before 59½, but it does not apply to IRAs or rollovers, so don't roll over funds if you plan to use this exception, say Fidelity Investments and this article from Charles Schwab. You must separate from service in the qualifying year, and the distribution must come directly from that specific employer plan, not an IRA.
It's good to be specific, but there's a danger in words such as “everything,” “nothing,” “never,” or “always.” “You always” and “you never” can be fighting words that can distract readers into looking for exceptions to the rule rather than examining the real issue.
How far back can the IRS go to audit my return? Generally, the IRS can include returns filed within the last three years in an audit. If we identify a substantial error, we may add additional years. We usually don't go back more than the last six years.
Entities that spend federal grant funds are required to submit an audit if they meet the following spending thresholds: $750,000 or more for Fiscal Years starting before October 1, 2024. $1,000,000 or more for Fiscal Years starting on or after October 1, 2024.