Many businesses unknowingly ignore economic nexus after expanding sales across multiple states. Economic nexus determines when a business must begin collecting and remitting sales tax based on its sales activity within a state.
Failing to comply with these rules can create significant financial risks. Businesses that exceed nexus thresholds but do not register for sales tax may accumulate back taxes, interest charges, and penalties over time.
If you are unfamiliar with economic nexus rules, begin with the overview guide: Economic Nexus Explained.
Why Businesses Ignore Economic Nexus
Businesses typically ignore nexus for several reasons.
- They are unaware of sales tax rules across multiple states
- They assume physical presence is required to collect tax
- They rely on outdated nexus laws before the Wayfair decision
- They grow quickly and fail to track sales thresholds
Many ecommerce companies and SaaS businesses expand nationwide before realizing that their sales activity may create nexus in multiple jurisdictions.
To determine whether your business has crossed nexus thresholds, you can use the Economic Nexus Calculator.
Back Taxes from Uncollected Sales Tax
When businesses fail to collect sales tax after crossing nexus thresholds, states may require payment of unpaid taxes from prior periods.
These taxes are often calculated based on total taxable sales within the state. Because sales tax was not collected from customers at the time of the transaction, the business may be responsible for paying the tax from its own revenue.
Back taxes can accumulate over several years before businesses discover the issue.
You can estimate potential exposure using the Sales Tax Exposure Calculator.
Interest on Unpaid Sales Tax
In addition to unpaid tax balances, states often charge interest on outstanding liabilities.
Interest is typically calculated from the date the tax should have been paid until the date the liability is resolved. Over time, interest charges can significantly increase the total amount owed.
Because nexus thresholds are often measured annually or over rolling periods, businesses may accumulate interest on multiple years of unpaid tax.
Sales Tax Penalties
States may also impose penalties when businesses fail to collect or remit sales tax after triggering nexus.
Common penalties include
- Late filing penalties
- Failure to collect tax penalties
- Failure to remit tax penalties
- Negligence penalties
Penalty amounts vary by state and may increase if compliance issues continue over multiple filing periods.
Sales Tax Audits
Ignoring economic nexus may increase the likelihood of a sales tax audit.
States use various data sources to identify businesses that may have triggered nexus but failed to register.
These sources may include
- Marketplace transaction data
- Shipping and logistics records
- Payment processor reporting
- Information sharing between state tax authorities
If a state determines that a business exceeded nexus thresholds, the state may initiate an audit to calculate unpaid tax liabilities.
How Businesses Resolve Nexus Exposure
Businesses that discover economic nexus exposure often take several steps to resolve the issue.
- Estimate historical tax liabilities
- Register for sales tax permits
- Begin collecting tax on future transactions
- Negotiate settlements through voluntary disclosure programs
Voluntary disclosure agreements can sometimes reduce penalties and limit the lookback period for unpaid taxes.
Why Identifying Nexus Early Matters
Identifying economic nexus early allows businesses to register for sales tax before significant liabilities accumulate. Monitoring thresholds helps businesses determine when registration is required and avoid unexpected compliance issues. Tools that track sales activity by state can help businesses monitor nexus obligations as they grow.
Related Sales Tax Resources
If you are evaluating sales tax obligations for your business, you can start with the Economic Nexus guide and the Sales Tax Nexus overview.
To review current thresholds across the country, see the Economic Nexus by State reference or explore additional guidance in the Sales Tax Nexus Hub.
Businesses analyzing potential liability can review the Sales Tax Exposure Analysis or estimate potential exposure using the Sales Tax Exposure Calculator.
If you track activity across multiple states, tools like the Economic Nexus Tracker and the Rolling 12-Month Nexus Tracker can help monitor thresholds.
You can also estimate whether your sales exceed state thresholds using the Nexus Threshold Calculator.
For a structured compliance overview, businesses may also review the Sales Tax Risk Report.
You can also review current state thresholds in the Economic Nexus Thresholds by State reference.
FAQs
What happens if a business ignores economic nexus?
Businesses may owe back taxes, interest, and penalties if they fail to collect sales tax after crossing nexus thresholds.
Can states audit businesses that ignore nexus?
Yes. States may initiate audits if they identify businesses that exceeded nexus thresholds but did not register for sales tax.
Do businesses have to pay sales tax they did not collect?
In many cases, businesses must pay the unpaid sales tax even if it was not collected from customers.
How far back can states collect unpaid sales tax?
The lookback period varies by state but may cover several years depending on the situation.
Can businesses reduce penalties for unpaid sales tax?
Some businesses resolve exposure through voluntary disclosure agreements that may reduce penalties and limit the lookback period.
