Proforma Invoice or Contract: What Actually Binds You?

Most China trade runs on paperwork no lawyer drafted: a proforma invoice as a PDF, a price confirmed in WeChat, a deposit wired, production started. Buyers ask me two opposite questions with equal anxiety. The first: “We never signed a contract — do we have one?” The second: “We only signed a PI — does it protect us?” The answer to both is the same, and it is worth understanding precisely, because it decides what you can claim when the deal goes wrong.

1. Deposit Wired Against a PDF: The Everyday Reality

Here is the sequence in a typical order: inquiry, quotation, proforma invoice naming the goods, price, quantity, delivery window and payment terms. You reply “confirmed,” wire the 30% deposit, the supplier acknowledges receipt and starts production. No contract book was ever signed. Both parties would say a deal exists — and Chinese law agrees with them.

That is the good news: your rights don't evaporate because nobody printed a signature page. The bad news is what “the deal” consists of. It is not the PI alone; it is the PI plus every chat message, every email revision, every payment record — a patchwork that a court has to stitch together after the fact. And courts stitch conservatively: terms nobody clearly agreed are treated as terms nobody agreed, and the law's default rules fill the gaps. Those defaults were written for generic transactions, not for your custom product. The PI binds you. It just rarely protects you.

2. The Legal Mechanics: How a PI Becomes a Contract

Chinese contract formation is formless on purpose, and the PRC Civil Code says so at each step:

• Any form counts. Article 469: a contract may be made in writing, orally, or in any other form — and electronic messages count as writing. Your email chain and WeChat record are not inferior evidence; they are the contract's medium.
• Offer and acceptance. Article 471: a contract is formed by offer and acceptance. The PI functions as an offer (or as your acceptance of the supplier's quotation); your confirmation and the deposit wire are acceptance by conduct.
• Performance cures the missing signature. Article 490: where the parties intended a contract in signed book form but it was never signed, and one party has performed its main obligation and the other accepted it — the contract is formed. You wired the deposit; they kept it and started production. That is performance plus acceptance. The contract exists.
• Online orders. Article 491: where goods or services are ordered online, the contract forms when the order submission succeeds. Relevant for B2B ordering portals and e-commerce workflows — the click is the signature.
• The battle-of-forms trap. Article 488: an acceptance that materially modifies the offer is not an acceptance — it is a new offer (a counter-offer). Now look at your own outbox: that reply “signed with comments,” where you changed the delivery clause and the penalty figure before returning the PI? You may not have accepted the deal — you may have killed the original terms and made a new offer the supplier never clearly accepted. The last unmodified version wins, or the modified points are simply not agreed.

One practical consequence of Article 488 that buyers miss: if you negotiate by emailing marked-up versions back and forth, the final effective terms are the last version returned without new changes — not necessarily the version you think you agreed. Keep the acceptance email that closes the loop. It is the single most valuable message in the file.

3. What Courts Reconstruct From PI + Chats + Payments

When there is no signed master contract, a Chinese court builds the deal from the record. Some elements are almost always recoverable, because money and logistics leave traces:

• Price — from the PI and the wire amounts (and the invoices that match).
• Quantity and specifications — from the PI, order emails, and production documents.
• Delivery terms and window — from the PI and follow-up chats; chat messages are admissible and routinely used. How Chinese courts treat chat evidence.
• Payment terms — from the PI and from how payments actually moved.

The element that is almost never in the record, and where disputes actually live, is the quality standard. “Same as sample” — which sample, sent when, confirmed by whom? AQL levels — agreed where? Without a written quality standard, the court falls back on mandatory national or industry standards, or the “usual standard” for goods of that kind. For a custom product, those defaults describe a product nobody designed. Most quality disputes I see are, underneath, a missing-standard problem that was cheap to fix at PI stage. How to write the inspection clause.

4. The Missing-Pieces Table

This is the honest accounting of what a PI-driven deal costs you. Each row: an element a real contract contains, and what happens in a dispute when the PI never had it.

PI element	If it's absent, what happens in a dispute
Quality standard	Court defaults to mandatory national/industry standards or the “usual standard” — your custom expectations are unprovable. This is the most common losing position.
Inspection period & method	You must object within a “reasonable time” after discovery — undefined, argued over, and goods may be deemed accepted if you waited or used them.
Liquidated damages clause	No preset delay penalty. Your compensation equals provable actual loss — which means your burden, your evidence, your expert reports.
Dispute forum clause	No forum chosen: the default is litigation at the defendant's domicile — the supplier's home court, on their turf, in Chinese.
Retention of title	None. Title passes on delivery per the default rules — unpaid-for goods sitting in your warehouse may already be yours in name only, with your claim converted into an unsecured debt.
Packaging standard	“Usual” packaging prevails. Transit damage becomes a fight about what “usual” means for fragile goods on a long ocean route.
Limitation of liability	Uncapped, both directions — but consequential losses still need proof of foreseeability. You get no protection and no predictability.

Read the table again and notice the pattern: the defaults are not catastrophic, they are just generic — and generic is exactly what a custom supply deal cannot afford to be.

5. When the PI Is Not Enough

Three situations turn a workable PI into a liability:

• Chat-negotiated terms that contradict the PI. The PI says FOB Shanghai; a WeChat message later says CIF Rotterdam including insurance. Which controls? The later agreement usually does — but proving later agreement means proving chat authenticity, sequence and context, which is a litigation exercise in itself. If terms were negotiated in chat, get them into a revised PI or an email both sides confirm.
• Amendments after signature. An email amendment to a signed contract raises the same battle-of-forms questions: did the other side actually accept the change, or keep performing under the original? Unsigned amendments are exactly where Article 488 does its damage.
• Side letters. A “confidential” supplement on pricing or rebates that contradicts the main document invites the other side to wave whichever document suits them that day. One deal, one document — and if the deal is bilingual, one hierarchy: see the language-trap guide on which text prevails in bilingual contracts.

6. Minimal Contract vs Full Contract

Not every order justifies a lawyer-drafted master agreement. The discipline is matching paperwork to exposure:

Minimal-contract checklist — for repeat orders below a modest threshold with a supplier you have verified:

1. Price, currency, Incoterms rule + year + named port.
2. Quantity, specifications, and a quality standard tied to a confirmed sample (reference number and date).
3. Delivery date, plus a simple per-week delay penalty and a cancellation right after a stated overrun.
4. Payment terms — with the payee account name matching the contracting entity, character for character.
5. One-line dispute clause (forum + governing law), even a short one.

Full-contract checklist — add for large orders, custom tooling, or any long-term relationship:

1. Retention of title or payment-security structure.
2. Inspection/AQL regime with rejection and re-work procedure.
3. Limitation of liability, and consequential-loss carve-outs.
4. Force majeure definition and notice mechanics.
5. Termination rights, return of tooling and materials, confidentiality.
6. Bilingual defined terms and a language-hierarchy clause.

The structure that scales: one master agreement, signed once, plus per-order PIs as binding annexes. Model wording: “Each Purchase Order / Proforma Invoice confirmed by both parties shall form an integral part of this Agreement. In case of conflict, this Agreement prevails, except as to price, quantity, specifications and delivery date specifically stated in the applicable PI.” One signature buys the legal machinery; each order buys only the commercial variables.

7. Cross-Border Wrinkles

• The entity on the PI vs the payee. The PI names Trading Co. A; the deposit instructions point to an account of Company B — or a personal account. If you wire anyway, you have just created the central dispute of your future case: who did I contract with, and who took my money? Apply the account name test before every wire. The account name test.
• The Hong Kong contracting entity. A PI from a HK shell with a mainland factory behind it is a recovery problem wearing a contract problem's clothes — winning against the shell is the easy part. The HK shell risk.
• When it has already gone wrong. If you are reading this with a deposit gone and no contract but the PI, the PI-plus-record case is still winnable — it is built, not found. How suing a Chinese supplier actually works.

The short version: the law meets you where the paperwork is. A PI is a real contract — thin, generic, and full of defaults. Sign the thin one for small orders with verified suppliers; upgrade before the order size makes the defaults expensive.

This article is general information, not legal advice, and does not create an attorney–client relationship. Statutory article references reflect the PRC Civil Code as currently in force and may change; outcomes vary by contract and by court. Nothing here is a guarantee of results.