Marketplace Facilitator Laws: Seller Checklist for 2026

Confirm the facilitator and covered transactions

A platform must meet the jurisdiction’s facilitator definition and applicable requirements. An advertising or referral site may not qualify, and some products, fees, or transactions may fall outside the platform’s collection responsibility.

Obtain the agreement, tax-registration evidence, state coverage, effective date, and order-level tax reports. Do not rely only on a checkout badge or general help-center statement.

• Name the responsible legal entity.
• Confirm coverage by state and product.
• Save permit or account evidence where available.

Map duties that stay with the seller

Sellers may still need to register or file, disclose marketplace sales, manage direct-channel collection, classify products, retain exemption certificates, respond to notices, and monitor physical and economic nexus.

A marketplace-only seller may receive simplified treatment in one state and still have a filing or registration obligation in another. Check before closing an existing account.

• Create a responsibility matrix by state and channel.
• Review direct website, invoice, wholesale, and phone orders.
• Do not cancel permits based on a platform assumption.

Monitor sales and inventory for nexus

Facilitated sales can count toward the seller’s economic nexus threshold depending on the state’s sales-base definition. Platform collection and threshold measurement are separate questions.

Fulfillment inventory may create physical presence. Request location reports and compare them with registrations and return footprints.

• Track gross destination sales by state.
• Review fulfillment locations monthly.
• Document whether marketplace sales are included in each threshold.

Handle exemptions, refunds, and customer service

The original collecting party should generally handle the related tax adjustment, but marketplace workflows differ. Refunds, partial returns, promotions, and chargebacks can create timing differences between seller systems and facilitator reports.

Define who receives exemption evidence and who answers tax questions. Preserve customer communications and link adjustments to the original transaction.

• Route tax refunds to the responsible collector.
• Avoid seller-issued tax credits for tax the seller never collected.
• Retain adjustment and exemption evidence.

Reconcile without double remittance

Record channel, destination, product, gross amount, taxable amount, tax collector, tax remitter, fees, refunds, and payout for every order. Separate facilitator-collected tax from seller-collected liabilities.

Reconcile gross marketplace orders to settlement statements, then map required marketplace disclosures to state returns. An unexplained difference should never be plugged into direct-sales tax.

• Book platform fees separately from revenue.
• Tie tax reports to orders and returns.
• Review every material channel variance.

Build a channel responsibility matrix

Create one row for every selling channel and destination state. Record the legal seller, marketplace facilitator, covered products, facilitator effective date, tax collector, tax remitter, refund owner, exemption owner, registration requirement, return disclosure, and evidence link.

This matrix prevents a common operational gap: tax assumes the platform owns the transaction while customer support or accounting processes it as a direct sale. It also reveals hybrid channels where the platform processes payment but may not meet the state’s facilitator definition.

Review the matrix when a platform changes its contracting entity, launches a new fulfillment service, adds a fee, or expands to a new state. Marketplace status is a legal and factual conclusion, not a permanent property of a brand name.

• Map each legal entity, platform, and state.
• Identify excluded products and fees.
• Name the owner of refunds and certificates.
• Link to platform agreements and official state guidance.

Use a monthly marketplace close checklist

Download order-level sales, tax, refunds, fees, and settlement reports before they expire from the platform. Reconcile gross orders to settlement activity, then reconcile facilitator-collected tax separately from amounts the seller collected on direct channels.

Investigate orders where the collector field is blank, the platform charged tax after a seller-issued exemption, a refund lacks a tax reversal, or a marketplace amount appears in the seller’s payable account. These exceptions are stronger controls than reviewing only aggregate totals.

Retain the platform’s registration evidence and responsibility statement with each period’s workpapers. California specifically tells marketplace sellers to keep documentation showing that the facilitator is responsible for collection and payment on facilitated sales.

• Archive reports in a consistent period folder.
• Tie settlements to cash and platform fees.
• Review state return marketplace disclosure lines.
• Escalate unresolved differences before filing.