Most rejected cover letters aren’t rejected for one dramatic reason — they’re rejected for two or three small, specific errors stacking up until the letter reads as generic, careless, or both.
Below are 25 of them, grouped by where they show up, with the reasoning behind each one — not just the mistake named, but why it costs you and what to do instead.
Opening mistakes
Your shift from generic templates to ATS-tested designs is exactly the kind of product decision I want to be making.
I am writing to express my interest in the Product Manager position at your company.
Four more openers reliably undercut a letter before it gets going:
- Starting with “My name is…” Your name is already on the document — in the header, the sign-off, often the filename too. Leading with it wastes the one sentence readers actually pay full attention to on something they already know.
- Restating the job title and where you saw it as the entire first sentence. “I am writing to apply for the Marketing Manager role I saw on LinkedIn” is purely logistical information the reader already has from the application itself — it tells them nothing about you.
- An opening identical to your last three applications, company name swapped. A hiring manager can’t see your other applications, but the sentence itself reads as generic regardless — vague enough to fit anywhere is the tell, not the reuse itself.
- Leading with a weakness or apology. “I know I don’t have much experience, but…” trains the reader to focus on the gap before they’ve seen anything that might outweigh it. Lead with evidence; address the gap later, briefly, if at all.
For a full bank of openers organized by situation, see cover letter openings, salutations & sign-offs, with examples.
Content and substance mistakes
The single most common complaint from hiring managers: a cover letter that just repeats the resume in sentence form. “As you can see from my resume, I have experience managing budgets and working with vendors” adds nothing a reader hasn’t already seen. “Managed a $50,000 event budget across three vendors, coming in 8% under budget” adds a number and a result the resume bullet alone might not have room for.
Four more show up constantly in the body specifically:
- Listing multiple achievements briefly instead of one in real detail. A cover letter that tries to summarize your whole career ends up as thin as the resume it’s meant to add depth to. One achievement, fully explained, beats four mentioned in passing.
- Claiming a skill with no example attached. “Excellent communication skills” is a sentence every applicant could write, true or not — it carries no information a hiring manager can act on. Attach the claim to a specific situation where you used it.
- Writing about what the company can do for you. “This role would help me grow my skills in a new industry” answers a question nobody asked. The letter’s job is proving what you bring, not what you’d gain.
- Padding length with filler sentences. A sentence that restates something already said, in slightly different words, is usually there to hit a word count rather than say something new — cutting it almost always makes the letter stronger, not weaker.
Tone mistakes
Over-apologizing is the most frequent one: “I know I don’t have much experience compared to other candidates, and I understand if that’s a concern, but I’m a fast learner” spends three sentences drawing attention to a weakness. Stating it once — “I don’t have professional marketing experience yet, but I’ve already run a real campaign end to end, under a hard deadline, with real stakes” — and moving straight to the evidence reads as far more confident.
Four more tone problems worth watching for:
- Sounding like an AI-generated template. Phrases like “I am excited to leverage my dynamic skill set” pattern-match to thousands of other letters a hiring manager has already read — the words are technically fine, but they carry zero signal that a specific person wrote them.
- Over-formality that doesn’t match the company’s actual tone. A stiff, corporate register applied to a casual startup’s application reads as not having done any research — check their careers page or LinkedIn presence before deciding how formal to be.
- Excessive flattery with nothing specific behind it. “I’ve always admired your company” without naming what specifically you admire reads as filler, since it could be written about any company with a functioning marketing department.
- Negativity about a previous employer. Even a factually accurate complaint about a bad manager or a toxic workplace raises a question in the reader’s mind about whether you’ll say the same about them one day. Frame any departure in forward-looking terms instead.
For a deeper look at spotting and fixing AI-sounding phrasing specifically, see how to use ChatGPT to write a cover letter.
Format mistakes
These are less about the writing and more about presentation — but they’re just as noticeable to a reader, and unlike a content weakness, they’re entirely avoidable with one proofread.
- Running past one page or 350 words. Length past that point reads as unedited rather than thorough — it signals the letter wasn’t tightened, not that you have more to say.
- A font or header style that doesn’t match the paired resume. Two documents from the same application that look like they came from different people undercut the consistency a hiring manager expects from a polished candidate.
- Margins narrowed to force extra text onto the page. This is usually visible at a glance — text crowding the edges of the page reads as a length problem solved the wrong way, rather than solved at all.
- Inconsistent spacing between paragraphs. A small, easy-to-miss detail on your own screen, but one that makes a document look unfinished the moment someone else opens it.
- Submitting a Word document when a PDF was implied or requested. Formatting can shift unpredictably across devices and Word versions — a PDF guarantees the reader sees exactly what you designed.
For the exact numbers — margins, font size, structure — see cover letter format: margins, fonts, length & layout rules.
Closing mistakes
“Thank you for your time and consideration. I look forward to hearing from you soon” is the passive default nearly everyone reaches for. “I’d welcome the chance to talk through how this experience applies to your team — I’m available for a call this week or next” asks for a specific next step instead of waiting for one.
Three more closing mistakes worth checking for:
- A closing that restates the entire letter. If your last paragraph summarizes everything already said, it’s using space that could instead ask directly for the interview — the summary adds nothing the reader hasn’t just read.
- No sign-off, or an overly casual one for a first application. “Cheers” or “Best” without “Sincerely” or “Best regards” as an option can read as slightly too familiar before you’ve established any actual relationship with the reader.
- Ending with a question that puts the burden on the employer. “What are the next steps?” hands the initiative back to them. Proposing your own availability for a call reads as more proactive.
Mistakes made when actually sending it
The last category has nothing to do with the writing and everything to do with the final send — and it’s often the most embarrassing kind of error, because it’s easy to catch with one careful pass.
Check these before you hit send
- The wrong company name anywhere in the letter — a clear sign it was reused without a full edit
- A file named “cover letter (2) FINAL FINAL.pdf” instead of something professional
- Attaching the wrong version of the letter entirely
- A subject line or filename that still references a different job title
The wrong-company-name mistake specifically is one of the fastest ways to lose credibility instantly — it doesn’t just look careless, it proves the letter was written for someone else first. Read the final version once, out loud, specifically checking every proper noun.
Fixing these systematically
Rather than proofreading for all 25 at once, work through the categories above in order — opening, then content, then tone, then format, then closing, then a final send-check. Catching one category cleanly before moving to the next is more reliable than one pass trying to catch everything simultaneously.
For the complete step-by-step process this checklist assumes you’ve already gone through, see how to write a cover letter.
Want to see what a mistake-free letter looks like for your specific field? Browse cover letter examples by profession.
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FAQ
What’s the most common cover letter mistake?
Restating resume bullet points in sentence form instead of adding new depth to one specific achievement. It’s the single most frequent complaint from hiring managers about cover letters generally.
Can one mistake get my application rejected outright?
Rarely on its own — a single formatting slip or a slightly generic opening usually isn’t disqualifying by itself. It’s the accumulation of several small issues that reads as careless or generic overall.
Should I have someone else proofread my cover letter?
Yes, if possible — a second reader catches wrong company names, awkward phrasing, and tone issues far more reliably than reading your own writing one more time.
Is it a mistake to use the same cover letter for multiple applications?
Reusing the structure is fine. Reusing it without updating the company-specific details — the opening line, any named detail — is the actual mistake, and it’s the one most likely to leave an obvious wrong-company-name error behind.
How do I catch mistakes in my own writing?
Read it out loud, check every proper noun specifically, and let it sit for at least a few hours before a final read — errors are much easier to spot after a break than immediately after writing.
Do formatting mistakes matter as much as content mistakes?
They’re usually easier to fix but no less visible — a font mismatch or crowded margins are the kind of thing a reader notices in the first two seconds, before they’ve evaluated a single sentence of your writing.
