An IRS audit doesn’t necessarily end when the federal process is complete. For companies, a federal audit can trigger a second wave of state tax obligations: amended returns, reporting requirements, filing deadlines, potential penalties, and, in some cases, refund opportunities.
In a recent GTM webinar, Kristen Schroeder and Mark Koch discussed these state tax implications following an IRS audit. Drawing on decades of experience and thousands of amended returns, they shared practical guidance on managing compliance and avoiding mistakes.
Early Communication Is Key
One of the first steps in managing the state consequences of an IRS audit is simple: communicate, communicate, communicate.
In larger tax departments, the federal audit team and state income tax team may operate separately, which can create problems if the state team doesn’t know when an agreement with the IRS has been reached. Coordination is critical to ensure that deadlines are established, shared, and eventually met. Once a triggering event occurs, a separate clock begins ticking for state filing requirements — and depending on the state, that deadline could be as short as 30 days.
Early communication between federal and state tax teams can help companies:
- Understand which state filing obligations will be triggered by the federal audit
- Coordinate state filing deadlines with existing compliance obligations
- Determine whether multiple amended returns may be required
- Identify potential tax, interest, and refund implications
- Gather the necessary information before it becomes difficult to locate
The importance of this coordination increases with the age and size of an audit. For example, GTM recently worked on a single project that involved more than 2,100 amended state returns.
When Does the Clock Start?
One of the questions we hear most frequently is: When do we have to start filing? Unfortunately, there is no standardized answer. States have different definitions of what constitutes a “final determination” for purposes of reporting federal audit adjustments.
To answer, you must pay attention to triggering events, such as IRS forms, agreements, tax payments, and refunds. Forms 870 and 870-AD are two common triggers, but even then, taxpayers need to consult the specific rules in each state rather than assuming a single deadline applies nationwide.
This lack of uniformity can make the process particularly challenging for companies filing in numerous states. Some states may require an amended return within 30 days, while others provide significantly more time. However, there is a possibility of more standardization on the horizon: The Multistate Tax Commission (MTC) has advocated for greater uniformity, including a 180-day reporting period tied to a clear definition of final determination.
Refunds, Interest and the Risk of Waiting
Federal audit adjustments don’t always result in additional tax. In some cases, they create significant state refunds.
That makes timing particularly important. A taxpayer who waits too long to report a refund may risk missing a state-specific filing deadline. At the same time, state systems may automatically reject a refund claim because it appears to fall outside the normal statute of limitations, even when the return is filed due to a federal audit. It’s also important to follow up with states after filing significant refund claims. State processing can take months or longer, so taxpayers may need to be proactive about checking the status of their claims.
The Paperwork Problem
One of the less obvious challenges of an IRS audit is simply figuring out how to translate federal audit information into state returns.
IRS audit adjustments are often presented on a consolidated basis. State tax returns, however, may require taxpayers to determine how those adjustments should be allocated among individual legal entities, creating significant additional work.
Tax departments can prepare by:
- Breaking down consolidated federal adjustments by legal entity
- Reconciling federal audit documents with state tax calculations
- Determining the appropriate state modifications
- Recalculating apportionment
- Tracking net operating losses, credits and other tax attributes
- Determining the correct starting point for an amended state return
- Providing states with documentation supporting the federal adjustments
In some cases, IRS documentation may not provide all the information a state auditor wants to see. In fact, GTM has encountered situations in which state authorities requested an entity-by-entity breakdown that was not included in the federal audit materials. This means taxpayers sometimes have to work backward from the federal information to develop the state-level calculations.
Don’t Forget About Other Federal Adjustments
IRS audits aren’t the only federal events that can trigger state reporting requirements.
Others include:
- Partnership audits
- Competent authority adjustments
- Mutual Agreement Procedure (MAP) agreements
- Amended federal returns
- Federal settlements and other agreements
These situations can become particularly complicated when they involve older tax years. A federal adjustment affecting a 2015 return, for example, may impact the state level years later — potentially creating a state refund claim or tax liability that appears to be outside the state’s ordinary statute of limitations.
Taxpayers may then have to demonstrate that the filing is connected to a federal audit or other qualifying federal adjustment.
A Solutions-Oriented Approach
The state tax consequences of an IRS audit can extend well beyond simply reporting the federal adjustment.
Companies may need to adjust their tax approach to account for different deadlines, filing requirements, state-specific rules, refund claims, interest calculations, documentation requirements, and tax attributes — sometimes across hundreds or, in extreme cases for large taxpayers, thousands of returns. This all needs to be done while maintaining day-to-day responsibilities, including current-year state and federal compliance.
Start by focusing on these considerations:
- Know your trigger dates: Understand exactly what event starts the state reporting clock in each jurisdiction.
- Communicate early: Make sure the state tax team knows what is happening with the federal audit.
- Track partial agreements: Don’t assume you can wait until the entire federal audit is complete.
- Protect refunds: Pay close attention to state-specific deadlines and refund statutes.
- Plan for multiple filings: A single federal audit can result in multiple amended state returns.
- Look beyond compliance: Federal adjustments may create opportunities to identify additional state tax savings.
The rules may not be uniform, but a proactive approach can help tax departments reduce risk, avoid unnecessary costs, and better manage the workload created by an IRS audit.
To learn more about managing the state tax implications of federal audits and amended returns, watch the full webinar here or contact our experts below.
