How do you handle sales tax when a supplier drop ships an order straight to your customer?

One Package, Two Separate Sales

The confusion around drop shipping comes from the fact that one box leaving one building represents two legally distinct transactions. Your supplier sells the item to you at wholesale, and you sell the same item to your customer at retail. The customer never sees the first sale and the supplier never sees your invoice, but a state tax auditor looking at the chain sees both. Each sale has to be evaluated on its own: is it taxable, who has the obligation to collect, and what is the taxable amount. Treating the shipment as a single event is the root cause of almost every drop ship tax mess we hear about. Related: How do you handle sales tax on shipping charges when selling to customers in different states?

The retail leg is the one you control. If you have nexus in the state where the package is going, whether from an office, an employee, inventory elsewhere, or crossing that state's economic nexus threshold, you charge your customer sales tax on the price you charged, at the rate for their delivery address. Your supplier's location is irrelevant to that calculation. The wholesale leg is the one that surprises people, because it is a sale for resale and should be exempt, but only if you can prove it with paperwork the supplier can accept and keep on file. Related: What Economic Nexus Means and Why It Matters

Keep reading: US Sales Tax Basics for Online Sellers, What Economic Nexus Means and Why It Matters, Origin vs Destination Based Sales Tax, Explained. See how SalesTaxly helps you us sales tax rates and lookup for online stores.

The Resale Certificate Is the Whole Ballgame

A sale for resale is not automatically exempt. It is exempt because the buyer documents it, and the document is a resale certificate. Give your supplier a properly completed certificate and the supplier stops worrying about the wholesale leg, because the certificate shifts the collection responsibility to you. Fail to give one and the supplier is left holding a taxable sale in a state where they very likely have nexus, so they will charge you tax on the wholesale price. That tax is not something you can pass to your customer or reclaim on a return you do not file, so it comes straight out of your margin.

The practical wrinkle is which certificate a given state and a given supplier will accept. Most states accept an out of state resale certificate that shows your registration number in your home state, and many accept the uniform multistate exemption forms that let you list several states on one document. A smaller group of states has historically insisted on a number issued by that state, which effectively means registering there before you can buy for resale into it. That list moves, so confirm current guidance for the ship to state rather than assuming last year's answer still holds.

When the Supplier Charges You Tax Anyway

Suppliers are cautious for a reason. If their certificate file is thin, they are the ones an auditor bills. So expect some suppliers to charge tax by default until your paperwork clears their compliance review, and expect a few to refuse certificates they consider incomplete, expired, or signed by someone who is not on the account. Build the certificate step into onboarding a new supplier, before your first order, not after a customer is waiting. Keep a simple register of which supplier has which certificate, which states it covers, and when it needs renewing, because several states expire certificates on a fixed cycle.

If tax does get charged on the wholesale leg, do not silently absorb it. Ask what the supplier taxed. In several states, when a drop shipper has to collect on the wholesale sale, the taxable base is meant to be the retail price the end customer paid if the supplier knows it, or the wholesale cost plus a markup if they do not. Knowing that rule sometimes turns a fixable invoice dispute into a credit memo. And check whether the same order also produced tax on your customer invoice, because double taxing one shipment is the fastest way to a refund request and a chargeback. Related: Product Taxability: Why Not Everything Is Taxed the Same

Wiring Your Store So the Numbers Line Up

Configure the store the way the retail leg actually works: tax is calculated on the customer's delivery address, using your nexus footprint, on your selling price including any handling you bill. Do not let a supplier's warehouse state leak into the calculation as an origin, and do not exclude drop shipped items from tax logic just because you never touched them. Shipping charges follow the ship to state's own rule for delivery charges, which is independent of who physically did the shipping. If you sell the same catalog through a marketplace as well, remember the marketplace collects on its own orders while you remain responsible for the ones placed on your site. Related: Sales Tax and Marketplaces: Who Collects

For bookkeeping, keep the two legs visibly separate. Wholesale purchases sit in cost of goods sold, and any tax the supplier charged you sits there too as an unrecovered cost, which is exactly the signal you want when a certificate is missing. Tax collected from customers is a liability, not revenue, and should reconcile to what you remit. Once a quarter, pull drop shipped orders and check three things: every supplier has a current certificate, no order was taxed on both legs, and the ship to states in that list still match the states you are registered in.