How to Write a Complaint Email to a Supplier

A useful complaint email to a supplier identifies the order, describes the problem and asks for a specific next step. Show the difference between what was confirmed and what arrived. Explain why that difference matters, then say what you would like the supplier to do.

For example, “The confirmation lists A4 frames, but we received A5 frames” gives the supplier something to check. “This order is completely wrong” does not explain which detail needs attention.

Give the supplier a clear problem to resolve

The British Council’s complaint-writing lesson recommends focusing on the essential facts, explaining the problem and stating the outcome you want. For a workplace order, organize those facts like this:

1. Identify the delivery: give the order reference and a relevant delivery date.
2. Describe the mismatch: compare the confirmed specification with what you received.
3. Explain the effect: say what you cannot do with the items, if that matters to the request.
4. Request a remedy: name the action you want and ask about the practical arrangements.

You do not need a long history of your relationship with the supplier. Include the details that help them find the order and understand the request.

This guide covers a first complaint about a delivery mismatch. If the goods have not arrived and you need their delivery status, use the asking for an update examples.

Choose a specific subject and a factual tone

A subject such as Order NF-418: incorrect frame size identifies both the reference and the issue. “Complaint” alone tells the recipient less.

In the body, distinguish an observation from an explanation you cannot verify:

Less useful wording	More specific wording
Your team ignored our order.	The confirmation lists A4 frames, but we received A5 frames.
We can’t use any of this.	Our printed A4 notices do not fit these A5 frames.
Sort this out immediately.	Could you arrange replacement A4 frames and confirm the delivery date?

These are original examples. The revised wording states the problem firmly without guessing why it happened. You can be courteous without apologizing for raising a legitimate concern.

Keep a requested outcome separate from a confirmed arrangement. “Could you arrange replacements?” makes a request. “Thank you for arranging replacements” suggests that the supplier has already agreed.

Practice: the notice frames are the wrong size

This scenario is fictional. You are Mina, writing to Jordan, your supplier contact. Use these facts:

• Order NF-418 was delivered on 12 October.
• The order confirmation lists 12 A4 notice frames. In this first version of the exercise, you have checked all 12 and they are A5.
• Your team’s printed A4 notices do not fit. You need the frames for an event on 20 October.
• You have a photo showing the delivered frames and their A5 labels, ready to attach.
• You want replacement A4 frames. The supplier has not agreed to a replacement, a delivery date or a return arrangement.

Write a subject and a complete email before reading the model. Include the mismatch, its effect and your request. Ask whether the correct frames can arrive before the event and what to do with the A5 frames.

Here is one possible answer:

Subject: Order NF-418: incorrect frame size

Hi Jordan,

I’m writing about order NF-418, delivered on 12 October. The confirmation lists 12 A4 notice frames, but all 12 frames we received are A5. Our printed A4 notices do not fit them.

I’ve attached a photo showing the frames and their A5 labels. Could you arrange replacement A4 frames and confirm whether they can arrive before our event on 20 October? Please also let me know how to return the A5 frames.

Best regards, Mina

The opening gives Jordan a reference and an exact comparison. The photo has a stated purpose. The request explains the timing need without announcing an unconfirmed delivery or return plan.

Only mention an attachment when you have included it. For more examples, see how to mention an attachment.

Revise when only part of the order is wrong

Now change the facts before sending the first email: a complete check shows that eight frames are the correct A4 size and four are A5. You still need 12 A4 frames for the event. Your attached photo shows the four incorrect frames and their labels.

Rewrite the problem and request paragraphs before reading the revision. Update both the quantity affected and the quantity you want replaced. Keep the eight correct frames out of the return request.

One possible revision is:

I’m writing about order NF-418, delivered on 12 October. The confirmation lists 12 A4 notice frames. Eight of the frames we received are A4, but four are A5 and do not fit our printed notices.

I’ve attached a photo of the four A5 frames and their labels. Could you arrange four replacement A4 frames and confirm whether they can arrive before our event on 20 October? Please also let me know how to return the four A5 frames.

Use the same subject, greeting and sign-off to make this a complete email. The revision requests four replacements, not a replacement of the whole order. Changing only “all 12” in the first paragraph would leave an unclear request later in the message.

Check the facts and the next step

Before sending, match the order reference, sizes and quantities to the confirmation and your actual checks. Make sure the request fits the problem you have described. Do not guess a return address or write as though a remedy has already been agreed.

If you are on the receiving side of a complaint, the customer complaint response guide covers acknowledging the problem and explaining the action you can take.

To practise your own workplace replies, start practicing for free. EmailBetter sends workplace scenarios tailored to your profile to your inbox. You write a reply in your usual email app, then review AI feedback in your dashboard.