Most writers spend seconds on a sign-off and move on. That's fine when the email is routine. It isn't fine when the message carries a complaint, a refusal, an apology, or a piece of news the reader won't want. In those situations, the closing words do real work: they set the emotional register your reader carries away from the message. Getting them wrong can unravel an otherwise careful email.
Why difficult emails need a different closing strategy
A standard "Kind regards" appended to an apology can read as indifferent. "Best wishes" after a refusal can feel sarcastic. The problem isn't that these sign-offs are wrong in general. It's that warmth-neutral closings clash with high-emotion content. Readers process the sign-off last, which means it shapes the emotional aftertaste of the whole message.
Difficult emails usually fall into four categories, and each one calls for a distinct approach.
- Apology emails: you've made an error or caused inconvenience
- Refusal emails: you're saying no to a request or proposal
- Complaint emails: you're raising a problem with a vendor, colleague, or client
- Bad news emails: you're delivering unwelcome information
Apology emails: close with accountability, not formality
When you've apologised in the body of an email, the sign-off should feel like the end of a conversation between two people, not the bottom of a form letter. "Kind regards" is too neutral. "Yours sincerely" is too stiff. What works is something that keeps the human register you set in the body.
These closings land well after a genuine apology:
- "With sincere apologies"
- "With apologies and appreciation for your patience"
- "Respectfully" (when the relationship is formal)
The word "sincere" earns its place here because it mirrors the emotional weight of the message. Don't use it as filler. If the apology in the body is specific and direct, "with sincere apologies" closes the loop. If the apology was vague or defensive, no sign-off can fix that.
One caution: avoid "warmly" after an apology email. It reads as though you've already moved past the problem when the reader hasn't.
Refusal emails: close without softening the decision
A refusal email that ends with "Hoping to work with you soon!" or "Best of luck with your search!" sounds hollow at best and condescending at worst. The reader knows you said no. Your sign-off can be professional and warm without pretending the refusal didn't happen.
"Kind regards" is actually solid here. It's neutral and professional. "Best regards" works too. What to avoid is anything that sounds like false encouragement or forced cheerfulness.
If the refusal is to someone you have an ongoing relationship with, a brief closing sentence before the sign-off does more than the sign-off itself. Something like "I hope we find a way to collaborate on a future project" followed by "Kind regards" lands far better than a warm sign-off tacked onto an otherwise cold message.
The real work of a refusal email happens in the body, not the sign-off. If you're still unsure how to frame the body of a difficult request, the principles in how to write a request email that gets a yes can be read in reverse: understanding what makes a request persuasive shows you what to acknowledge in a polite refusal.
Complaint emails: close with a clear next step
A complaint email that ends without signalling what you expect next leaves the reader uncertain. That uncertainty often produces inaction. Your closing words should point at the resolution you want, and your sign-off should match the tone of professional firmness rather than outrage or excessive politeness.
"Regards" works. "Yours faithfully" works if the letter is formal. What doesn't work is "Thanks in advance" (it presumes compliance) or anything that softens the complaint so much that the reader doesn't take it seriously.
When the complaint is internal and you're writing to a colleague or manager rather than a vendor, the tone shifts. You don't want to sound adversarial. "Best regards" or even "Thanks" (when used deliberately) can signal that you're raising a professional concern, not starting a conflict. Knowing how to handle the emotional pitch of these messages connects directly to the broader skill of replying to a rude email professionally, because the same tone calibration applies in reverse.
Bad news emails: close with continuity
Bad news emails carry a specific risk: the reader feels dropped. They've absorbed something unwelcome and then the email just ends. A closing sentence that signals you remain available, or that the relationship continues, does real work before the sign-off lands.
Something like "Please don't hesitate to reach out if you have questions" followed by "Kind regards" reads as human and supportive without being saccharine. For more serious news, "With sincere regards" or simply "Sincerely" provides gravity without coldness.
Avoid "Best wishes" in bad news emails. The word "wishes" sounds passive, as if you're handing the problem to luck. "Regards" in any form signals professionalism. "Sincerely" signals genuine engagement with the reader.
A quick-reference guide
These pairings won't fit every situation, but they cover the most common cases. The key principle is consistency between your closing sentence, your sign-off, and the emotional tone of the body.
- Apology: "With sincere apologies" or "Respectfully"
- Refusal: "Kind regards" or "Best regards"
- Complaint (external): "Regards" or "Yours faithfully"
- Complaint (internal): "Best regards" or "Thanks"
- Bad news: "Sincerely" or "Kind regards"
The one sign-off to avoid across all difficult emails
"Cheers" doesn't belong in any difficult business email. It's a fine closing for routine, friendly messages. In a difficult email, it signals that you haven't taken the situation seriously, or that you didn't notice the emotional weight of what you wrote. The reader notices.
Similarly, "Take care" lands badly after a refusal or a complaint. It can read as dismissive. "Have a great day" after delivering bad news is almost always the wrong call. These phrases don't fail because they're impolite. They fail because they're mismatched: the message and the sign-off are pulling in different directions, and readers feel that tension even when they can't articulate it.
Sign-off choice is a small decision. In difficult emails, it's one of the last decisions the reader uses to judge whether you handled the situation well. That's reason enough to make it deliberately.
For a broader look at how sign-offs function across the full range of professional emails, how to write a business email sign-off that fits covers the full spectrum, including the register differences between "regards," "sincerely," and "best."