The question of whether to write "congratulations on" or "congratulations for" trips up careful writers more than you'd expect. Both prepositions appear in professional emails, cards, and speeches, and both can sound correct to a native speaker. The difference is real, though, and getting it wrong can make your message feel slightly off, even if the reader can't name the reason.
The short answer
"Congratulations on" is the standard choice in most situations. You use it before a noun or a gerund (an -ing verb acting as a noun) that names the achievement itself.
- Congratulations on your promotion.
- Congratulations on winning the contract.
- Congratulations on completing the project.
"Congratulations for" works when you want to emphasise the reason someone deserves recognition, rather than the achievement itself. It points toward a quality or action that earned the praise.
- Congratulations for handling that negotiation so well.
- Congratulations for staying calm under pressure.
Both forms are grammatically correct. "On" is simply more common in formal and professional writing, which is why defaulting to it keeps your message sounding polished.
Why "on" dominates in professional writing
English treats achievements as events or milestones, things that happened at a point in time. The preposition "on" marks the connection between congratulations and that event. "Congratulations on your new role" links the expression of praise directly to the milestone.
"For," by contrast, signals cause or justification. It answers the question "why?" rather than "what?" That framing is slightly more unusual in professional correspondence because it implies the achievement needs defending or explaining. In practice, that's rarely the intent, so "on" avoids any unintentional undertone.
The gap narrows in spoken English and informal writing, where the two prepositions are nearly interchangeable. In a formal letter or a business email, stick with "on" unless you have a deliberate reason to use "for."
The gerund rule: a practical test
When the object of "congratulations" is a verb, convert it to a gerund (add -ing) and pair it with "on." This almost always produces the more natural sentence.
Say you want to acknowledge a colleague who closed a deal. "Congratulations on closing the deal" reads cleanly. "Congratulations for closing the deal" is not wrong, but it sounds slightly like you're awarding a prize rather than sharing in someone's success. One word, a genuine difference in warmth.
If you're unsure which to use, ask yourself: am I pointing at the achievement, or am I explaining why the person deserves praise? Achievement points to "on." Explanation points to "for."
Common mistakes to watch for
"Congratulations of" is incorrect and surprisingly common in non-native English writing. There's no grammatical role for "of" here. Delete it and replace it with "on."
"Congratulations about" appears occasionally. It's not standard and sounds awkward. Avoid it in professional writing entirely.
Dropping the preposition entirely, as in "Congratulations your promotion," is simply a missing word. It happens in rushed emails. Proofread before sending.
Finally, watch the spelling. "Congratulations" takes all five syllables: con-grat-u-la-tions. The abbreviated "congrats" is fine in casual messages, but use the full word in formal correspondence. A misplaced shorthand can undercut an otherwise professional tone, much the way the wrong closing phrase can color a reader's impression of your whole message. That same logic applies when you're weighing phrases like "looking forward to" vs "I look forward to", where one variant reads as warmer and one as more formal.
How to congratulate someone in a business email
The preposition is only part of the sentence. The rest matters too. A congratulatory message that buries the praise under a wall of qualifications lands flat.
Lead with the congratulations itself. Don't open with "I wanted to reach out to say..." Just say it. "Congratulations on your appointment as regional director" is a complete, punchy first sentence. It puts the achievement front and center, which is where the reader's attention is anyway.
Follow with one specific detail. "The work you put into the Hartfield account clearly paid off" is better than a generic "you've worked so hard." Specificity signals that you actually noticed.
If the email serves a professional purpose beyond the congratulations, a brief transition keeps things clean. "I'd also love to connect once you've had time to settle into the new role" moves the message forward without burying the original sentiment.
Tone calibration matters as well. A note to a long-term colleague can afford informality. A note to a senior stakeholder or an external contact calls for the full word, a measured tone, and a professional sign-off. When you're deciding how formal the whole email needs to be, it helps to think about the salutation too: greetings and salutations set the register before your reader reaches the body.
A note on "congratulations on your" vs "congratulations for your"
When the possessive "your" follows the preposition, "on" is almost always the right call. "Congratulations on your new baby," "congratulations on your retirement," "congratulations on your award." These are standard phrases that native speakers use without hesitation.
"Congratulations for your" is not ungrammatical, but it reads as foreign or slightly old-fashioned in modern professional English. Merriam-Webster lists "congratulations on" as the primary construction. That's the safe default in any professional context.
Quick reference
Use "congratulations on" when naming the achievement directly, whether it's a noun ("your promotion") or a gerund ("winning the pitch"). Use "congratulations for" when you're explaining the quality or action that earned the praise. Avoid "congratulations of," "congratulations about," and any spelling shorter than the full word in formal writing. When in doubt, "on" is correct.