Sales Tax and VAT for Online Sellers: A Beginner's Guide

Few topics cause more initial anxiety for new online resellers than sales tax and VAT. When a seller makes their first $1,000 in sales across eBay, Vinted, or Poshmark, questions immediately arise: Do I need a state tax permit? Am I responsible for sending tax money to 45 different states? How do European VAT rules work?

The good news is that modern marketplace tax infrastructure has simplified transactional sales tax significantly. However, understanding how taxes affect your pricing, payouts, and record-keeping is essential to running a legitimate, stress-free resale operation.

1. US Resellers: Marketplace Facilitator Laws

Prior to 2018, online sellers were theoretically responsible for tracking sales tax across different states where they had economic presence ("nexus"). That changed with the Supreme Court's South Dakota v. Wayfair decision, which led nearly every state to pass Marketplace Facilitator laws.

Under Marketplace Facilitator legislation:

• The Platform Collects the Tax: When a buyer in California buys your $50 jacket on eBay, eBay automatically calculates California's local sales tax (e.g. 9.5% = $4.75) and charges the buyer's card $54.75.
• The Platform Remits the Tax: eBay sends that $4.75 directly to the California Department of Tax and Fee Administration. That money never touches your checking account, and you do not need to file sales tax returns in California.
• Applies Across Platforms: This automatic collection is handled seamlessly across eBay, Poshmark, Mercari, Depop, and Vinted.

2. IRS Form 1099-K & Income Tax Record Keeping

In the United States, online marketplaces report gross payment volume to the IRS using Form 1099-K. Crucially, Form 1099-K reports gross transaction volume, not your profit. If you sell $10,000 of inventory on eBay, your 1099-K will show $10,000.

To avoid paying income tax on gross revenue, you must maintain clean bookkeeping records showing your deductible expenses:

1. Cost of Goods Sold (COGS): Receipts or written ledger logs of thrift store purchases, estate sale buys, or inventory wholesale invoices.
2. Marketplace Fees: Platform commissions, promoted listing ad fees, and transaction charges.
3. Shipping Postage & Supplies: Pirate Ship charges, polymailers, boxes, bubble wrap, and thermal labels.
4. Sourcing Mileage: Business miles driven to source inventory (tracked with mileage logging apps).

3. UK & European Sellers: VAT & DAC7 Rules

In the UK and European Union, the regulatory framework differs in two fundamental ways:

Tax-Inclusive Pricing

In Europe, consumer law mandates that retail prices shown to consumers must include Value Added Tax (VAT). If you list a dress for €30 on Vinted France, the buyer pays exactly €30 plus shipping/buyer protection. In contrast, US platforms add sales tax on top at the final payment screen.

UK VAT Registration Threshold

In the United Kingdom, casual sellers and small sole traders do not need to register for or charge VAT until their rolling 12-month taxable turnover reaches the £90,000 threshold. Below this threshold, you do not charge VAT on your sales.

DAC7 & HMRC Digital Platform Reporting

Under EU Directive DAC7 and equivalent UK HMRC rules, online platforms must annually report seller transaction data to tax authorities if a seller meets either of the following criteria within a calendar year:

Meeting this threshold does not automatically mean you owe tax—it simply means the platform shares your sales total with tax authorities. If you are selling personal used items at a loss compared to what you originally paid at retail, no capital gains or income tax is typically owed.

How to Calculate Net vs Gross Amounts

If you need to calculate tax-inclusive or tax-exclusive prices, use our mathematical formulas:

To master pricing strategies that absorb fee overhead comfortably, read our guide on Reselling Profit Margins Math or compare platform fees on our Vinted vs Depop vs eBay Breakdown.