Scaling Your Marketplace: Five Tax Challenges to Solve Early

Online marketplaces have seen enormous growth in recent years. Businesses across industries are embracing them to scale faster and reach new customers. But with growth comes complexity—especially when it comes to tax. Regulators worldwide are tightening rules, and marketplaces are increasingly being held responsible for tax compliance. If overlooked, these requirements can delay launches and eat into profits. 

Here are five common tax pitfalls to watch for—and how to avoid them from day one. 

1. Deemed Supplier Rules 

Many jurisdictions now treat marketplaces as the “deemed supplier,” meaning you're responsible for collecting and remitting tax on behalf of sellers. But figuring out who’s liable—marketplace, seller, or buyer—isn’t always straightforward. 

Factors like product type, seller and buyer location, and buyer business status all affect tax liability. These rules vary by jurisdiction and even by item. In the U.S., things are simpler—but extra fees like bag taxes and digital service levies are adding complexity. 

If you miss a tax obligation, audits can lead to penalties. That’s why it’s critical to understand liability rules before you launch. 

Vertex for Marketplaces automates tax determination based on local facilitation rules—so you stay compliant without slowing down. 

2. VAT ID Validation 

To assign tax liability correctly, you need to know whether your sellers and buyers are businesses. This means validating VAT IDs—either during onboarding or at checkout. 

Manual validation is time-consuming and error-prone. Rules and sources differ by country, and keeping records for audits adds another layer of complexity. 

Vertex Validator automates VAT ID checks in real time, helping you apply reverse charge mechanisms and reduce friction. 

3. Back-to-Back Invoicing 

Some jurisdictions require marketplaces to issue two invoices per transaction: 

• One between the seller and the marketplace
• One between the marketplace and the buyer 

These invoices must meet local compliance standards and be audit-ready. Formats vary, and mistakes can lead to fines. Vertex supports compliant invoice generation—including self-billed and back-to-back formats—integrated with Mirakl workflows. 

4. E-Invoicing  

Countries like Italy, France, and Saudi Arabia now require e-invoicing for B2B and B2C transactions. These are machine-readable documents sent directly to tax authorities in real time. 

It’s not just about sending invoices—it’s about integrating with government systems and meeting strict formatting rules. Vertex e-Invoicing streamlines creation, exchange, clearance, and archiving—so you’re always audit-ready. 

5. Global Reporting  

Marketplace growth means more transactions—and more reporting. Monthly tax filings can overwhelm your team and introduce errors. 

Vertex for Marketplaces offers a user-friendly reporting suite and API integration, so data flows directly into your systems. That means less manual work and fewer mistakes. Visit this page for a deeper look at what to consider when choosing financial compliance reporting tools. 

Scale with Confidence 

Tax shouldn’t be an afterthought. With the right tools, it doesn’t have to be a barrier to growth. Vertex and Mirakl helps marketplace operators think about compliance from the start. With certified integration, you can automate liability assignment, VAT validation, invoicing, and reporting—so you scale globally without tax surprises