Marketplace Facilitator laws have quietly become a compliance minefield for thousands of sellers, and that's created a goldmine for tax professionals who know how to navigate it. States are now requiring online platforms—Amazon, eBay, Shopify, and more—to collect and remit sales tax on behalf of third-party sellers, but the rules vary wildly by jurisdiction. If you're a sales tax compliance expert, this is your moment to build a serious service business around helping sellers understand their obligations and avoid penalties.
Why Marketplace Facilitator Compliance Matters Now
States have collected over $1.5 billion in additional sales tax revenue since facilitator laws rolled out in 2018, and they're tightening enforcement every year. A seller who thinks they're off the hook because Amazon collects tax in their state could be dead wrong—facilitator laws don't eliminate seller responsibility; they often just shift the burden. For example, a seller operating on multiple platforms might be subject to different collection rules depending on which state they're selling in and whether that state has a facilitator law in place.
The real problem: most small business owners have no idea whether their state requires them to register, file separate returns, or maintain records. This confusion is your entry point to offer high-value compliance services.
Key Service Opportunities for Your Practice
Multi-state registration and filing. Many sellers operate across 5–15 states but only register in one or two. You can offer a service to map their sales activity by state, determine filing requirements, and handle registration ($150–$400 per state, depending on complexity). Bundle this with quarterly or annual compliance monitoring.
Nexus analysis and sales tax exposure audits. Help clients understand where they have sales tax nexus and what they actually owe. This involves reviewing their Seller Central dashboards, transaction histories, and marketplace-specific tax reports. A thorough audit typically costs $1,500–$4,000 and can reveal thousands in back-tax liability before a state auditor does.
Platform-specific tax reporting. Each marketplace reports sales differently to states. Amazon issues a 1099-K and separate tax reports; Shopify integrates with some states' systems but not others; eBay has its own facilitator agreements. Offering specialized guidance on interpreting these reports and reconciling them with actual tax returns is a sticky, recurring service.
Streamlined Sales Tax (SST) compliance. If your clients qualify for the SST program (it simplifies multi-state compliance), you can position yourself as the expert who gets them certified and keeps them compliant. This typically involves annual audits and documentation updates.
Pricing Models That Work
Most tax professionals in this space use three approaches:
- Flat project fees: $2,500–$6,000 for a complete nexus analysis, registration, and first-year compliance setup for a multi-state seller.
- Hourly retainers: $150–$250/hour for ongoing quarterly reviews and state-specific guidance. Many clients need 8–12 hours per quarter.
- Per-state registration packages: $300–$500 per state to handle registration, initial filings, and documentation, with add-on fees for amended returns or audit defense.
The most profitable approach: combine a flat setup fee with a recurring quarterly retainer. You'll build predictable revenue while your clients get peace of mind.
How to Attract These Clients
Marketplace seller communities are hungry for this expertise. Target your marketing toward:
- Sellers in high-volume categories (electronics, apparel, beauty) where tax nexus is complex
- Businesses crossing state lines for the first time
- Sellers who've received state tax notices or audit letters
- E-commerce accountants who need to sub out tax compliance work
Write case studies showing before-and-after scenarios: "Seller registered in 3 states, discovered they owed tax in 8 more—we helped them become compliant and negotiate a payment plan." These resonate.
List your services on Mercoly to get found by business owners actively searching for sales tax and use tax compliance help—you'll stand out as a specialized provider and generate qualified leads faster than generic directories allow.
Frequently Asked Questions
Q: What's the difference between what a marketplace facilitator collects and what I still owe? Facilitators only collect sales tax; they don't handle use tax, county taxes, or local jurisdictions in many states. You're still responsible for these additional obligations even if your state's facilitator law passes.
Q: How do I know if I need to register for sales tax in a state that has a facilitator law? You still need to register if you have other nexus (like employees, warehouses, or drop-ship partners in that state), even if the marketplace is collecting. Check your state's revenue department website or consult a tax professional to be certain.
Q: Can I get penalized for back taxes a marketplace facilitator should have collected? In most states, no—but you're liable for periods before the facilitator law took effect and any sales outside their collection scope. Get an audit defense plan in place immediately if you've been selling for years.
Start building your marketplace facilitator compliance practice today—the demand is growing faster than the supply of qualified professionals.