As filing season approaches, online retailers face a familiar risk: scrambling through hundreds of state and local tax filings, scrambling to reconcile remote-seller activity, and discovering gaps just when deadlines are looming. With hundreds of jurisdictions, evolving rules and multiple platforms feeding sales data, you cannot afford to treat sales tax compliance as an afterthought.
Use this checklist to turn filing season into a managed, repeatable process rather than a compliance fire drill.
1. Confirm Your Nexus Footprint
- Review all states where you had sales last year. Many states impose economic nexus thresholds (e.g., > $100,000 in remote sales or > 200 transactions) that trigger a tax-collection obligation.
- Identify physical or affiliate triggers: warehouses, fulfillment centers, remote employees, or referral affiliates in a state.
- For each state where nexus exists, confirm you hold a valid sales tax permit and your registration is active.
2. Review Taxable Products and Exemptions
- Audit your product catalog: Are you selling tangible goods, digital goods or services? Taxability varies state to state.
- Ensure you have exemption certificates on file for customers claiming resale or non-taxable status.
- For each exemption certificate, check that it is valid, signed, dated and tracked by state and type of sale.
3. Verify Your Automated Tax-Calculation Setup
- Confirm that your sales tax automation tool or platform integration is pulling the latest rate tables, jurisdiction boundaries and filing thresholds.
- Sample 20-30 transactions by state: Ensure tax charged equals the correct state and local combined rate for the ship-to address.
- Check whether you are capturing marketplace sales or marketplace-facilitated sales correctly per state rules.
4. Reconcile Collected vs. Remitted Tax
- Download your sales-by-state report and reconcile against your general ledger and prior year filings.
- Flag discrepancies: missing registration in a state but collecting tax, over-collection in a state you weren’t registered, or no tax collected when one should have been.
- Use your automation system’s filing module (or list of permits) to confirm each state’s return was filed and tax remitted on time.
5. Prepare for Return Filing and Remittances
- Create a calendar of all filing deadlines for each state where you’re registered (monthly, quarterly, annual).
- Archive confirmation of each filing and payment receipt in a searchable compliance folder.
- If you have late filings or amended returns, keep remediation logs and internal reviews to support audit readiness.
6. Build Your Audit-Ready Documentation
- Maintain a single “compliance binder” (digital or physical) with: nexus documentation, registration certificates, exemption certificates, filing confirmations, collected tax vs remitted reports, automation logs.
- Define roles: who monitors nexus triggers, who approves exemptions, who oversees filings. Clear ownership reduces risk of oversight.
- Run an internal “reverse audit” of one past quarter: pick a random sample of transactions, trace tax logic, review customer billing, and log any remediation actions.
7. Review and Update Automation and Systems
- If you’re relying on spreadsheets or manual rate imports, evaluate the cost of error and time drain.
- Check that your automation solution supports multi-state standards, marketplace rules, and integrates cleanly with your platform or ERP.
- Set a recurring review: each quarter update your list of states where sales increased, thresholds were met, or filings changed.
Stay Ahead This Filing Season
Start filing season ahead of the curve. Use this checklist to systematically confirm nexus, collect the right tax, reconcile filings, and maintain audit-ready documentation.
If you’re still relying on manual tax processes or spreadsheets, it’s time to upgrade your platform. Automation is no longer optional—it’s the only reliable way to keep growing without tax exposure.
Book a call with a CereTax specialist and build a tax operation that scales with your ecommerce business.
