Complaint Letter to a Supplier (B2B): Template + Example

Your letter is legal notice

Under the Uniform Commercial Code, which governs sales of goods in every US state except Louisiana, a buyer who has accepted goods "must within a reasonable time after he discovers or should have discovered any breach notify the seller of breach or be barred from any remedy" (UCC 2-607(3)(a)). Miss that window and you lose the claim itself, along with the goodwill.

Which clock you are on depends on whether you accepted the goods. You accept under UCC 2-606 by saying so, by acting as the owner, or simply by failing to reject after a reasonable chance to inspect. If instead you are rejecting the delivery, the timing is tighter and it starts earlier: rejection must come within a reasonable time after delivery or tender, and it is ineffective unless you seasonably notify the seller (UCC 2-602(1)). List every defect a reasonable inspection would show, because UCC 2-605 stops you relying later on a visible defect you left out, and between merchants the seller can force the issue by asking in writing for a full and final list. Until the goods are collected, hold them with reasonable care at the seller's disposal and do not use, resell, or scrap them (UCC 2-602(2)), following any instructions the seller gives for perishable or resalable goods.

Do not aim at the floor on content. The official comment says the notice need only be enough "to let the seller know that the transaction is still troublesome and must be watched," then adds that it must inform the seller "that the transaction is claimed to involve a breach." Courts split over which sentence controls, and between merchants many take the stricter reading: a service request or a grumble about performance is not notice unless it says you treat the supplier as in breach and look to them for a remedy. Write it that way and the split stops mattering, which is why the sample letter below opens with the words "formal notice of breach." The clock is also stricter for you than for a consumer, because the lenient standard exists to protect a good-faith retail buyer rather than commercial parties. A merchant is expected to inspect and speak up.

Buying across a border, or outside the US

If your supplier sits in another country, check which law governs the sale before you rely on the UCC. Where both parties have their places of business in countries that have signed the UN Convention on Contracts for the International Sale of Goods, the Convention applies by default and displaces Article 2 unless your contract opts out. It is stricter on content than the UCC: Article 39 says you lose the right to rely on a defect unless your notice specifies its nature, given within a reasonable time of discovering it, and in no event later than two years after the goods were handed over. Naming the defect precisely, as the sample below does, satisfies both regimes. The UK has never signed the Convention, so a US to UK contract turns on whichever law the contract chooses.

In the UK, business-to-business sales still run on the Sale of Goods Act 1979, which the Consumer Rights Act 2015 replaced only for consumer contracts. The structure mirrors the American one. You are deemed to have accepted goods under section 35 when you tell the seller so, when you act inconsistently with their ownership, or when you keep them beyond a reasonable time without rejecting, and section 35(2) protects you until you have had a reasonable opportunity to examine them. Acceptance ends the right to reject and leaves you with damages. Section 35(9) is why this is the business rule: the examination safeguard cannot be contracted away against a consumer, but between businesses your contract can set its own shorter inspection window. Section 15A adds a trap for buyers who are not consumers, since a breach of the implied terms too slight to make rejection reasonable is treated as a claim for damages rather than a right to reject.

Other Commonwealth jurisdictions run their own descendants of the same Victorian statute rather than the UK Act itself: the state and territory Sale of Goods Acts in Australia, the provincial Acts in Canada, the Sale of Goods Act 1930 in India, and Part 3 of the Contract and Commercial Law Act 2017 in New Zealand. The examination and rejection machinery is close enough that the letter below works in all of them, but cite your own statute rather than this one.

Send it the way your contract requires

Most supply agreements carry a notices clause: it names the method (post, recorded delivery, sometimes email), the address, the person or role it must go to, and when notice is deemed received. A complaint typed into a chat window with your sales rep may keep the relationship moving, but it may not be notice under the contract. Check the clause first, send the letter that way, and copy the account manager separately so the commercial conversation keeps running. Where the contract is silent, email the named contact and follow with a signed PDF or a posted copy you can prove was delivered.

What to include

• Both parties and the contract. Your company details, the supplier's, the date, and a subject line naming the purchase order or agreement.
• The order. PO number and date, the item codes and quantities ordered, and the delivery date the contract required.
• What happened on delivery. Delivery date received, batch or lot numbers, inspection findings, and the delivery note or waybill reference.
• How you established the discrepancy. Annotate and countersign the delivery note at the point of receipt ("260 received, 140 short"), raise a goods-received note, photograph the consignment sealed and unloaded, and name who counted and when. Where transit loss is possible, notify the carrier in parallel. A shortage claim that rests on a bare assertion invites the answer that your people signed a clean proof of delivery.
• The clause you are relying on. Quote or cite the delivery, specification, or quality term the supplier missed.
• The operational impact, quantified. Hours of line downtime, expedite freight you paid, orders you could not fill.
• The remedy you want, and the date. Take it from the list below and name the amount.
• Enclosures. Copies of the PO, delivery note, inspection report, and photographs. Keep the originals.

Name a remedy your contract gives you

"We expect compensation" invites a discount voucher. Ask for the specific thing:

• Redelivery of the shortfall by a stated date, at the supplier's cost.
• Replacement or repair of the nonconforming goods, with collection arranged by them.
• A credit note for the value of goods not delivered or rejected.
• A price adjustment where you accepted goods that are usable but below specification.
• Recovery of direct costs the breach caused you, such as expedite freight or third-party inspection, where the contract allows it.

Give a deadline in the letter. Ten to fourteen business days is the customary first-response window in supplier correspondence, and a shorter one is defensible when a line is down. Say what you will do if the date passes, in plain terms.

One caution: holding back payment looks like the obvious pressure point and can itself put you in breach. Only set off against an invoice where your contract gives you that right, or where a statutory right of set-off applies. If you are unsure, pay and pursue the remedy, or take advice before you hold the money.

A complete example

A short and late delivery of components, with the impact quantified and the remedy named.

The template

Type your own details in and leave the clause references where they are: they are what turns the letter into notice rather than a grumble. Both this skeleton and the worked letter above sit in the .docx.

Tone: firm, and still commercial

You will likely buy from this supplier again, and the person reading your letter is often the one who has to argue your case internally. Give them what they need to do it: precise references, a defensible number, and a remedy their finance team can sign off. Keep blame out of it and put the breach in the record instead. A letter that reads as a file note rather than an outburst is also the one that looks best if a lawyer reads it later.

If the deadline passes

• Escalate inside the supplier. Send the same letter up to the account director or commercial manager, referencing the unanswered original by date.
• Use the contract's dispute procedure. Many agreements require a formal notice, then a management meeting, then mediation or arbitration before court. Skipping steps can cost you later.
• Reassess supply. Dual-source the affected item and record the incident in your supplier scorecard, so the commercial consequence is real.
• Letter before action. Where the sum justifies it, a formal pre-action letter setting out the breach, the loss, and a final deadline is the last step before proceedings. Take advice before sending it.

Judge the reply against the clauses you cited rather than its tone. An adequate one accepts or disputes the breach in terms, commits to a specific remedy in the amount you claimed, and fixes a date for performance. An apology that promises to "look into it" moves nothing, and the deadline in your letter keeps running while you wait. If your own company is on the receiving end of a customer complaint, our guide to replying to a complaint letter covers the consumer side of the same exchange.

For what your own paper has to carry, how to reference the letter so it can be found later, and who is authorised to sign it, see business letter format. If you are setting the page itself, the spacing and the position of each block are in formal letter formats.

Sources

• Uniform Commercial Code 2-607(3)(a) and official comment 4: notice of breach after acceptance within a reasonable time or be barred from any remedy; the comment's two standards (transaction "still troublesome" and "claimed to involve a breach"); the lenient reading is aimed at retail consumers rather than merchants.
• UCC 2-606 (what counts as acceptance), 2-602 (rejection within a reasonable time after delivery, and the duty to hold rejected goods with reasonable care at the seller's disposition), 2-603 (merchant buyer's duties on the seller's instructions), 2-605 (waiver of defects not stated, including the between-merchants written request).
• UCC Article 2 adopted in every US state except Louisiana, which applies its Civil Code to sales.
• UN Convention on Contracts for the International Sale of Goods, Article 39: notice specifying the nature of the non-conformity, within a reasonable time and no later than two years after handover; the UK is not a contracting state.
• Sale of Goods Act 1979 sections 35, 35(2), 35(9) and 15A: deemed acceptance, the reasonable opportunity to examine, the business-contract position, and slight breach as damages for non-consumer buyers. The Consumer Rights Act 2015 replaced the 1979 Act for consumer contracts only.
• Commonwealth equivalents: state and territory Sale of Goods Acts (Australia), provincial Sale of Goods Acts (Canada), Sale of Goods Act 1930 (India), Contract and Commercial Law Act 2017 Part 3 (New Zealand).
• Supplier correspondence practice on first-response windows of ten to fourteen business days.

This page is general information about business complaints and sale-of-goods notice, not legal advice. For advice on your situation, consult a qualified professional.