When Tax Authorities Call, Every Decision Matters
An IRS audit letter, a 30-day letter proposing adjustments, or a state tax assessment can threaten financial stability, disrupt business operations, and lead to prolonged legal battles. Without the right guidance, even minor missteps early in the process can escalate into costly liabilities or missed appeal deadlines.
Erik Lincoln, JD, CPA, holds a dual JD/CPA credential and brings Big Four and BigLaw tax experience to every audit, appeal, and litigation matter he handles at Lincoln PLLC. He understands both the legal and accounting sides of a dispute, which lets him anticipate how the IRS or a state Department of Revenue will approach a case before the other side does. Every decision counts, and we help clients make theirs with confidence.
How an IRS or State Tax Dispute Moves Through the System
Most tax controversies follow a predictable sequence: an audit or examination, a proposed adjustment, an opportunity to protest or appeal, and, if unresolved, litigation in Tax Court or the appropriate forum. Where you are in that sequence determines what options are still available and how urgently you need to act.
Two Deadlines That Matter Most
30-Day Letter
After an audit, the IRS typically gives 30 days to request an appeal with the IRS Office of Appeals before the proposed adjustment becomes final.
90-Day Letter (Notice of Deficiency)
If the dispute isn’t resolved at Appeals, taxpayers generally have 90 days to petition the U.S. Tax Court before the assessment becomes enforceable.
See the IRS’s own explanation of these rights in Topic no. 151, Your Appeal Rights. Missing either deadline can forfeit the right to appeal or litigate, so the earlier an attorney is involved, the more options remain on the table. For a visual walkthrough of how a dispute typically branches from here, see our IRS tax dispute resolution decision tree.
Types of Tax Controversy Matters We Handle
We represent U.S. and foreign businesses, business owners and investors, and, as referrals, CPAs and attorneys whose clients face unusual tax disputes. Disputes that arise out of a merger, acquisition, or other business transaction often overlap with our M&A tax counsel work, since a deal’s structure can shape how an audit or adjustment plays out later.
IRS Tax Disputes & Resolution
- Audits & Examinations
- Tax Appeals & Litigation
- Penalty Abatement
- BBA Partnership Audits
- Withholding & Employment Tax Issues
- Foreign Account & Asset Reporting
- Streamlined Filing Compliance
- Cross-Border Transactions & IRS Scrutiny
- Tax Exempt
State Tax Disputes & Resolution
- State Tax Disputes (incl. NC / NCDOR)
- State Tax Audits & Appeals
- Penalty Abatement
- Withholding & Employment Tax Issues
- Tax Amnesty & Voluntary Disclosure
BBA partnership audits in particular follow their own centralized procedure under the Bipartisan Budget Act. See our BBA audit rules guide for CPAs for how that process differs from a standard individual or corporate audit. Types of audits we handle: individual income tax, business income tax, state franchise tax, property tax, excise tax, qualified plans, international forms, sales and use tax, payroll and employment tax, foreign asset disclosure, gift and estate tax, tax-exempt entities, and withholding tax. Our full library of tax charts and case law covers many of the underlying rules referenced above in more technical depth.
Our Service Model
Strategy Call
A one-hour strategy call to discuss your IRS or state audit, appeal, or litigation issue before committing to representation.
Tax Audit Representation
Send us your IRS or state correspondence so we can review your situation and outline how we can help, tailored to how much or how little support you need.
Appeals & Tax Court
Send us your 30-day letter so we can review it and outline the process for preparing a protest to the IRS Office of Appeals, or representing you in Tax Court litigation.
Penalty Abatement
Send us your audit report so we can assess whether you may qualify for relief and outline next steps. Our IRS civil tax penalties chart breaks down the penalty categories most likely to qualify.
How We Approach Your Case
- ✓Strategic Engagement with Tax Authorities: Building credibility with IRS and state auditors through clear, well-supported responses and effective communication positions clients for the strongest possible resolution.
- ✓Managing the Audit Process: anticipating adjustments before they become points of contention, controlling the scope and flow of information, and managing deadlines and negotiations tactically.
- ✓Navigating Appeals & Litigation: negotiating with the IRS Office of Appeals or pursuing Tax Court litigation while minimizing client risk and exposure.
- ✓Minimizing Future Risk: strengthening compliance and tax reporting strategies after a case closes so the same issues don’t resurface.
What to Do if You Receive an IRS or State Audit Notice
Read the notice carefully to identify what’s being requested and the response deadline. Avoid responding to the IRS or state agency directly until you understand what the notice actually alleges. If you’ve already received a 30-day letter or a Notice of Deficiency, note that date immediately, as it starts the clock on your appeal or Tax Court rights described above.
From there, gather the underlying records the notice references, and bring in a tax controversy attorney before your first substantive response goes out. Early involvement is what allows us to control the scope of an audit rather than react to it after the fact.
Frequently Asked Questions About Tax Controversy and IRS Disputes
Recent Tax Controversy Insights
Facing a Tax Dispute? Take the First Step Toward Resolution.
Erik Lincoln, JD, CPA, brings a dual credential and Big Four and BigLaw experience to audits, appeals, litigation, and penalty relief for businesses, investors, and the CPAs and attorneys who refer them. Learn more about our team, or reach out through our contact page to schedule a consultation.