A complaint letter requests some sort of compensation for defective or damaged merchandise or for inadequate or delayed services. While many complaints can be made in person, some circumstances require formal business letters. The complaint may be so complex that a phone call cannot effectively resolve the problem; or the writer may prefer the permanence, formality, and seriousness of a business letter. The essential rule in writing a complaint letter is to maintain your poise and diplomacy, no matter how justified your gripe is. Avoid making the recipient an adversary. 

Note: Complaints by e-mail may not be as effective as those by regular mail, so that option is not included here.

1. Early in the letter, identify the reason you are writingto register a complaint and to ask for some kind of compensation. Avoid leaping into the details of the problem in the first sentence.
2. Provide a fully detailed narrative or description of the problem. This is the “evidence.”
3. State exactly what compensation you desire, either before or after the discussion of the problem or the reasons for granting the compensation. (It may be more tactful and less antagonizing to delay this statement in some cases.)
4. Explain why your request should be granted. Presenting the evidence is not enough; state the reasons why this evidence indicates your requested should be granted.
5. Suggest why it is in the recipient’s best interest to grant your request; appeal to the recipient’s sense of fairness or desire for continued business, but don’t threaten. Find some way to view the problem as an honest mistake. Don’t imply that the recipient deliberately committed the error or that the company has no concern for the customer. Toward the end of the letter, express confidence that the recipient will grant your request.