How To Write A Reference Letter For A Coworker

Writing a reference letter is mostly about picking the right facts and not overselling them

Most people waste an hour writing something generic that gets filed immediately. The trick is deciding what the hiring manager actually needs to know and leaving out the rest. You have to be specific. Generic praise like "great attitude" tells someone nothing. Specific examples do. Start with your relationship. State how long you worked together, in what capacity, and whether you reported to the same person or worked on shared projects. That establishes credibility. If you managed them, note it. If you were peers who collaborated daily, say that too. Then pick two or three concrete accomplishments. Not ten. Two or three. I once wrote a letter for someone who was excellent at everything, and I spent forty minutes trying to summarize her entire career. The result was six paragraphs of blur. The recruiter later told me the candidate wished she'd picked fewer stories because the strong ones got buried. So choose what matters most.

For each accomplishment, include context, action, and result. Context is what was happening. Action is what they did. Result is what happened because of it. A recruiter can tell when a bullet point is just a responsibility rather than an achievement. Closure should be direct. No flourishes. State whether you would rehire them and under what conditions, if any. The honest answer always reads better than the rehearsed one. I ran into a situation last year where a coworker had been on a performance improvement plan during part of our overlap. The manager asking for the reference was aware of this. I could have glossed over it, and honestly most people would. Instead I wrote that she met her PIP goals within ninety days and hasn't missed a target since. It came across as factual rather than evasive, and the hiring team appreciated that she hadn't been hidden from them.

There is a counter-intuitive point here. Sometimes the most valuable reference letters acknowledge a gap or a weakness briefly, then explain how the person responded to it. A perfect narrative reads like marketing copy, and recruiters are trained to spot that. A measured letter feels earned. Keep the format simple. Business letter style, no more than one page. Address it to "Hiring Manager" unless you know the name. Use a neutral tone. Avoid exclamation marks. Do not use first-person pronouns excessively, but don't sound like a robot either. Common mistake: repeating job description language. If their resume already says they "led cross-functional initiatives," your letter does not need to echo that phrase. Say something the resume does not say.

Another mistake: writing for the wrong audience. Reference letters are read by HR screeners first, then hiring managers. HR wants verification of claims and red flags. Hiring managers want proof of impact. Include both. There is a timing factor most people ignore. Sending the letter within 48 hours of the request signals reliability. Waiting two weeks looks like indifference or a lack of organization. Even if you need to draft it slowly, send a quick acknowledgment that you are working on it. If you are unsure whether you know the person well enough to write a strong letter, say so. It is better to decline than to write a tepid endorsement that does more harm than good. A polite decline keeps your professional reputation intact.

The final check is straightforward. Read the letter aloud. If it sounds like something you would say in a real conversation, keep it. If it sounds like something you wrote to fill space, cut it. Reference letters are legally binding statements in some jurisdictions. Do not exaggerate. Stick to what you can verify. That protects you and the person you are recommending.