Materiality Matters: Why Not Every Sales Tax Error Deserves Equal Attention
One of the biggest misconceptions in sales and use tax compliance is the belief that every error deserves the same level of scrutiny. The reality is that tax professionals, auditors, and businesses all operate with limited time and resources — and not every issue deserves equal attention.
One of the biggest misconceptions I see in sales and use tax compliance is the belief that every error deserves the same level of scrutiny. While every business should strive for accuracy, the reality is that tax professionals, auditors, and businesses all operate with limited time and resources.
That's where the concept of materiality comes into play.
The Wisconsin Department of Revenue trains its auditors on materiality, emphasizing that tax issues should be addressed in a reasonable and practical manner and that auditors should focus their efforts on issues that have merit and significance.
As someone who has spent decades helping businesses navigate sales tax audits and compliance challenges, I couldn't agree more.
What Is Materiality?
Materiality is defined as the importance or significance of an amount, transaction, or discrepancy. In other words, materiality asks a simple question: Does this issue matter enough to warrant further attention?
Notice what materiality is not.
Materiality is not a free pass for businesses to ignore tax compliance. It is not an excuse to underreport sales or overlook use tax obligations. Instead, it is a practical framework for deciding where resources should be focused to achieve the greatest compliance impact.
Materiality Should Drive Compliance Priorities
Many businesses approach sales tax compliance by treating every issue as equally important. That approach often leads to wasted time.
Let's say a manufacturer spends five hours researching a $50 tax issue while ignoring a recurring exemption certificate problem that could create tens of thousands of dollars in audit exposure. Technically, both are tax issues. Practically, one deserves much more attention.
Materiality helps businesses prioritize. Rather than asking, "Is there an issue?" the better question is: "What is the potential tax impact if this issue is wrong?"
Four Questions to Evaluate Materiality
There are several factors auditors should consider when determining whether an issue is material. Those same factors can be valuable for businesses conducting self-reviews.
What Is the Tax Effect?
The first consideration is the size of the adjustment. In sales and use tax, the tax effect often matters more than the transaction amount itself.
- A $10,000 transaction taxed incorrectly may create only a few hundred dollars of additional tax.
- A recurring exemption certificate issue affecting millions of dollars of sales may create significant exposure.
Focus on the tax consequence, not just the transaction size.
How Large Is the Business?
Context matters. A $2,000 error might be material for a small business reporting $500,000 in annual sales. That same error may be insignificant for a company generating $100 million in revenue. Materiality is not determined in a vacuum. The size and complexity of the taxpayer influence whether an issue warrants deeper review.
Is the Issue Ongoing?
This is one of the most overlooked factors. An isolated error may have limited consequences. A recurring error can become very expensive. Auditor training specifically highlights whether the transaction or issue exists in future periods as an important materiality consideration.
A small mistake repeated thousands of times becomes a big problem.
For example, incorrectly taxing a single invoice may not be significant. Applying the same incorrect tax treatment across multiple years and hundreds of transactions can quickly create audit exposure.
What Is the Risk?
Materiality is not solely about dollars. Risk matters too. Auditors are encouraged to consider the likelihood that a discrepancy exists.
- Prior audit findings
- Complex exemption claims
- Related-party transactions
- Multi-state sales activity
- Industry-specific compliance challenges
The higher the risk, the more valuable a detailed review becomes.
Materiality Can Change During an Audit
One of the most important lessons is that materiality is not static. Auditors are instructed to reassess materiality as additional records become available because an issue's significance can change throughout the audit process.
Businesses should adopt the same mindset. Perhaps an issue initially appears insignificant. Later, you discover it affects multiple years or multiple locations. What looked immaterial yesterday may become highly material tomorrow.
That's why periodic reviews of sales tax processes are so important.
Professional Judgment Still Matters
Auditors are reminded that materiality must be evaluated on a case-by-case basis and that professional judgment is critical. Auditors are encouraged to consult with supervisors or peers when uncertainty exists.
The same principle applies to businesses. There is no universal dollar threshold that automatically determines whether an issue is material. Every situation is different. Industry, transaction volume, audit history, risk level, and future exposure all play a role.
That is why experienced sales tax professionals can often identify concerns that appear small at first glance but have major long-term implications.
Don't Ignore Future Audit Consequences
One point from the training deserves special attention. Auditors are cautioned to think about how their decisions may affect future audits and to remain mindful of reliance on past audit work.
Businesses should think the same way. If a compliance issue is identified today but left unresolved, what message does that send during the next audit? What happens if the issue continues for another three years?
Materiality is not just about current exposure. It is about preventing future exposure as well.
The Bottom Line
Materiality helps businesses focus their compliance efforts where they matter most. The goal is not to ignore tax issues. The goal is to allocate resources intelligently, address meaningful risks, and avoid spending valuable time chasing insignificant items while larger problems remain unresolved.
One of my favorite takeaways from the Wisconsin training was a quote from Peter Drucker:
"There is nothing so useless as doing efficiently that which should not be done at all."
— Peter Drucker
The best compliance programs are not the ones that look at everything equally. They are the ones that identify the issues that truly matter and address them before an auditor ever walks through the door.
Not Sure Where Your Biggest Sales Tax Risks Are?
Holly Hoffman is a former WI Dept. of Revenue auditor and the owner of Sales Tax Advisory Network, LLC. She helps businesses identify material compliance risks before an auditor does.