The 3PL and Remote Fulfillment Pivot

Your inventory sits in a warehouse in Kentucky or Nevada. You have never been there, you do not employ anyone there, and the building belongs to Amazon or ShipBob or a regional 3PL. The question you keep getting different answers to is whether that pallet has pulled you into the U.S. tax system. It is actually two questions, and they have two different answers.

One warehouse, two separate tests

The first question is statutory. Does holding inventory in the United States, and filling U.S. orders from it, make you engaged in a trade or business within the United States under IRC §864(b), so that the sorting rules of §864(c) apply to your income?

The second question is treaty-based. If you are resident in a country with a U.S. income tax treaty and you claim its benefits, does the warehouse give you a permanent establishment under the treaty's Article 5, so that the United States may tax your business profits at all?

These are not the same test and they do not have to produce the same result. The IRS says so in its own examiner training material on permanent establishments: "the nature and amount of activities that would lead to a foreign company being engaged in a U.S. trade or business are broader than those that would create a U.S. permanent establishment." A seller can be inside the Code's definition and outside the treaty's. That gap is the entire subject of this piece, and conflating the two is the mistake that produces confident wrong answers on both sides.

The statutory question: inventory, activity, and agency

Neither the statute nor the regulations address marketplace fulfillment programs by name. The analysis runs on general principles, which means it runs on facts.

The threshold standard from case law is whether the U.S. activity is considerable, continuous, and regular. Two older cases frame the range. In Commissioner v. Piedras Negras Broadcasting Co., 127 F.2d 260 (5th Cir. 1942), a foreign enterprise selling to U.S. customers without a U.S. operating presence was not engaged in a U.S. business. In Handfield v. Commissioner, 23 T.C. 633 (1955), a Canadian producer of postcards sold them in the United States through a news company acting as his agent under a distribution agreement, and the court found him engaged in business here.

Handfield is the closer analogue to modern fulfillment, and the reason is worth stating plainly. What mattered was not the physical location of the goods alone. It was that a person in the United States was carrying on the selling function for the foreign principal on a continuing basis.

Three factual variables drive the statutory analysis in a fulfillment arrangement.

• Whose inventory is it. If title stays with you until the customer buys, you own goods sitting in the United States and being sold from there. If you sell the goods to a U.S. buyer at the border and that buyer resells, the U.S. selling activity is someone else's.
• Who performs the selling function. Receiving, picking, packing, and shipping is one thing. Soliciting, negotiating, pricing, and handling customers is another.
• How continuous the pattern is. A single container cleared through a U.S. warehouse in a one-off transaction sits differently from a replenishment cycle that never stops.

Where an agent is involved, Treas. Reg. §1.864-7(d) supplies the framework the IRS uses. An agent's U.S. office is attributed to the foreign principal only if the agent is not an independent agent acting in the ordinary course of its own business, and either has and regularly exercises authority to negotiate and conclude contracts for the principal, or holds a stock of the principal's merchandise from which orders are regularly filled. That second clause is the one that makes practitioners look twice at fulfillment arrangements. Note the limit on its reach: §864(c)(5) applies for purposes of the office-based rules of §864(c)(4)(B), and Treas. Reg. §1.864-7 defines when you have a U.S. office. Having no attributed office does not by itself answer the threshold question of whether you are engaged in a U.S. trade or business.

Where title passes, and why sourcing turns on it

Sourcing is a separate step from the trade-or-business question, and it is often the step that decides how much is actually taxable.

For goods you buy and resell, IRC §861(a)(6) sources income from the purchase of inventory outside the United States and its sale within the United States to the United States. Where the sale occurs is a title question. Treas. Reg. §1.861-7(c) provides that a sale "is consummated at the time when, and the place where, the rights, title, and interest of the seller in the property are transferred to the buyer," and where bare legal title is retained, the place where beneficial ownership and risk of loss pass. The same regulation contains an anti-avoidance rule: if the transaction is arranged in a particular manner for the primary purpose of tax avoidance, all factors of the transaction are examined instead, including negotiations, execution of the agreement, the location of the property, and the place of payment.

For goods you manufacture, the rule is different and it changed. IRC §863(b), as amended in 2017, allocates and apportions income from the sale of inventory produced by the taxpayer "solely on the basis of the production activities with respect to the property." A foreign manufacturer that produces abroad and sells into the United States sources that income by reference to where production happens, not where the sale closes. A reseller does not get that answer. This single distinction separates two sellers whose warehouses look identical.

One more provision belongs on the list. IRC §865(e)(2) sources income from a nonresident's sale of personal property to the United States when the sale is attributable to a U.S. office or fixed place of business, with a limited exception for inventory sold for use outside the United States where a foreign office materially participated.

The treaty question: does the warehouse make a permanent establishment

If a treaty applies to you, Article 5 typically defines a permanent establishment as a fixed place of business through which the business of an enterprise is wholly or partly carried on, then removes a list of activities from that definition. The U.S.–Germany convention is a representative example. Its Article 5(4) provides that a permanent establishment shall be deemed not to include "the use of facilities solely for the purpose of storage, display, or delivery of goods or merchandise belonging to the enterprise," or "the maintenance of a stock of goods or merchandise belonging to the enterprise solely for the purpose of storage, display, or delivery."

Read the word solely. The carve-out covers storage, display, and delivery, and nothing beyond it. Where the same location also performs sales, order negotiation, customer contracting, or after-sale servicing that goes past logistics, the exclusion stops applying on its own terms.

The residual carve-out in most treaties covers a fixed place maintained solely for activities of a preparatory or auxiliary character. The IRS practice unit on this exception states the working criterion: "The decisive criterion is whether or not the activity of the fixed place of business in itself forms an essential and significant part of the activity of the enterprise as a whole." It adds that a fixed place whose general purpose is identical to the general purpose of the whole enterprise is not preparatory or auxiliary.

Treaty terms vary. The list of excluded activities, the wording of the agency paragraphs, and the presence or absence of an overarching preparatory-or-auxiliary condition differ from convention to convention, and protocols amend them. Some treaties have been modified to narrow these carve-outs. The IRS instructs its own examiners that "every U.S. income tax treaty is different" and that the permanent establishment article and any protocols must be read in each case. Do not import Germany's paragraph 4 into your treaty because it reads well.

Dependent agent, independent agent, and the 3PL

Article 5 of a typical treaty adds an agency route to a permanent establishment. Under the U.S.–Germany formulation, a person other than an independent agent who acts on behalf of an enterprise and "has, and habitually exercises" authority to conclude contracts in the name of the enterprise creates a permanent establishment for the activities that person undertakes. A separate paragraph provides that an enterprise is not deemed to have a permanent establishment merely because it carries on business through a broker, general commission agent, or other agent of independent status acting in the ordinary course of business.

A commercial 3PL that serves many unrelated customers, sets its own methods, prices its services, and bears its own business risk looks like an independent agent in the ordinary course of its own business. A logistics provider that works only for you, follows your detailed instructions, bears none of the risk, and holds itself out as your U.S. operation looks less like one. The treaty agency test also asks about contracting authority, and a warehouse that only receives and ships is not concluding contracts on your behalf.

Two answers, one filing posture

An illustrative case. A seller resident in a treaty country buys finished goods from a manufacturer in Asia, ships them to a U.S. fulfillment center, and sells through a marketplace. Title to the goods stays with the seller until a U.S. customer buys. All pricing, listing, and customer service is handled from abroad. Under the Code, the position that the seller is engaged in a U.S. trade or business is at least arguable, given inventory held and orders regularly filled in the United States, and the sales income would be U.S.-source under §861(a)(6) if title passes here. Under the treaty, the same seller may have a strong argument that the fulfillment center falls inside the storage and delivery carve-out and no permanent establishment exists.

Those two answers coexist. The practical consequence is that the treaty position has to be claimed and disclosed rather than assumed. A treaty-based return position is generally reported under IRC §6114 on Form 8833, and IRC §6712 sets the penalty for failure at $1,000, or $10,000 for a C corporation. Treas. Reg. §1.882-4(a)(3)(vi) allows a protective Form 1120-F where the taxpayer concludes its limited U.S. activities produce no effectively connected income, which preserves access to deductions and credits under the 18-month rule of Treas. Reg. §1.882-4(a)(3)(i) if that conclusion is later found to be wrong.

What to gather before anyone answers

The determination is documentary. Pull the fulfillment agreement and read what it says about title, risk of loss, and who is authorized to act for whom. Establish the moment title passes to your customer under your terms of sale. Confirm whether you produce the goods or resell them, because §863(b) and §861(a)(6) send those two facts to different places. Map every person in the United States who touches a customer, including contractors. Then read your own treaty's Article 5, in full, with its protocols.

None of this is a conclusion about your situation, and no article can supply one, because the answer moves with the contracts. A review of the actual documents is what settles it, and the firm's cross-border diagnostic is built for that. Related material is collected under IRS exposure analysis.