Cover letter mistakes that get an application rejected

A cover letter can lose an application on its own, separate from whatever the resume underneath it says. A 2024 Zety survey of 753 American recruiters and HR professionals found that 81% have rejected a candidate based solely on details in their cover letter, and 87% consider the cover letter an essential factor in deciding who gets an interview at all. That's a higher bar than most job seekers treat it as, especially anyone who still writes the cover letter last and fastest, on the theory that the resume is what actually matters.

The position worth stating early: the same Zety survey, and the mistakes it documents, point to a short, specific list of failures, not a vague sense of "quality." Formatting, customization, typos, length, and the email address at the top of the letter each show up as a named, counted reason recruiters give for rejecting application materials. This piece works through each one, in the order recruiters actually cite them, with a worked rewrite so the fix isn't just theoretical.

The mistakes, ranked by how often recruiters cite them

Mistake	How often recruiters cite it as a reason for rejection
Lies or exaggerations	76%
Poor formatting	72%
Not customized to the role	72%
A typo anywhere in the application	68%
An unprofessional email address	61%

These figures, from the same Zety report, describe reasons recruiters give for rejecting application materials broadly, resume and cover letter together, since the two are rarely judged in total isolation from each other. The cover letter is frequently where several of these mistakes are most visible first, since it's often the first full paragraph of prose a recruiter reads from a candidate, ahead of the more structured, bulleted resume.

Mistake 1: a letter that could have been sent to any company

This is the mistake recruiters cite almost as often as formatting problems, at 72%. A cover letter that never names the specific role, team, or something concrete about the company reads as a form letter the moment the second sentence starts, and recruiters who read dozens of these a week notice the pattern immediately.

What it looks like: "I am excited to apply for this position at your company. I believe my skills and experience make me a strong candidate." Nothing in that sentence would need to change if it were sent to a different company for a different role.

The fix: Name the actual role title, reference something specific from the job ad, usually a named responsibility or requirement, and tie your opening achievement to it directly. "I'm applying for the Senior Marketing Coordinator role because the job ad's focus on lifecycle ownership is exactly the kind of scope I've been building toward" does the same job in roughly the same number of words, while being unmistakably about this one job.

Mistake 2: formatting that looks like it was never proofread as a document

72% of recruiters cite poor formatting as a rejection reason, and a cover letter is particularly exposed here because it's read as continuous prose rather than skimmed as bullets the way a resume is. Inconsistent fonts, a missing date or address block, single-spaced walls of text with no paragraph breaks, and letters that are clearly a resaved copy of a previous application with one company name swapped out but formatting artifacts left behind, all fall into this category.

The fix: Four or five short paragraphs, consistent font and spacing matching your resume, a proper greeting and closing. If you're reusing a previous letter as a starting point, read the entire thing once more before sending, specifically looking for a leftover reference to the wrong company or role.

Mistake 3: a typo anywhere in the application

68% of recruiters name a typo as a reason they've dismissed a candidate. The specific detail worth noting is "anywhere in the application," not just the cover letter itself, which means a clean cover letter sitting on top of a resume with one typo doesn't fully protect you, and the reverse is equally true.

The fix: Read the letter out loud before sending it, since your eyes skip over errors your ear catches. Check the company name and the hiring manager's name specifically, since those are the two details most likely to carry over incorrectly from a previous application, and also the two most visible to the specific person reading it.

Mistake 4: an unprofessional email address

61% of recruiters cite this specifically, which surprises people who assume it's a minor detail compared to the letter's content. An email address like "partyanimal99@" or a childhood nickname sitting at the top of an otherwise professional letter undercuts the letter before the recruiter reads a single sentence of it.

The fix: A simple firstname.lastname address, through any major provider, costs nothing to set up and removes this as a factor entirely. If your existing address is tied to an old job or an outdated handle, a new one dedicated to your job search is a five-minute fix with an outsized return given how often this specific detail gets cited.

Mistake 5: exaggerating or inventing a detail

76% of recruiters cite lies or exaggerations as a dismissal reason, the single most-cited mistake in the whole survey. In a cover letter specifically, this usually shows up as an achievement stated with more certainty or scale than the facts support, "I single-handedly grew revenue by 200%" when the real contribution was one part of a larger team effort, or a skill claimed at a level the interview will immediately expose as thin.

The fix: State your actual, specific contribution, scoped honestly. "I contributed to a campaign that grew revenue 200% as part of a four-person team" is more credible, not less, than an inflated solo claim, and it survives a follow-up question in an interview the way an exaggeration does not. Our guide to quantifying resume achievements covers the same honesty-with-specifics discipline for the resume side of the same application.

Mistake 6: the wrong length

Zety's recruiters split fairly evenly on preferred length: 49% prefer around half a page, 26% prefer a full page, and 25% prefer just a few sentences. There's no single right answer here, but the mistake is writing a letter that doesn't match any of these norms, two and a half pages of dense paragraphs, or three sentences so thin they read as an afterthought.

The fix: Default to roughly half a page, three to four short paragraphs, since that's the single most commonly preferred length across the surveyed group. If the job ad or application portal gives a specific length guideline, follow that over this general default.

A worked rewrite: before and after

Before: "To Whom It May Concern, I am writing to apply for the open position at your company. I have attached my resume for your review. I have many years of experience and strong skills that I believe make me a great fit. I am a hard worker and a fast learner. I look forward to hearing from you. Thank you for your consideration."

This opening makes nearly every mistake on this list at once: no specific role name, no company detail, no concrete achievement, and adjectives standing in for evidence throughout.

After: "Dear Priya Nair, I'm writing to apply for the Customer Success Manager role at Northwind, specifically drawn to the job ad's focus on reducing churn across enterprise accounts. In my current role, I rebuilt our onboarding process for enterprise clients, cutting first-90-day churn from 22% to 14% over the past year. I'd welcome the chance to bring that same focus to Northwind's enterprise book."

Same opening job, roughly the same length, but every sentence now does work the first version didn't: a named recipient, a named role, a specific detail pulled from the job ad, and one real number that couldn't be copied unchanged into a letter for a different company.

A short pre-send checklist

1. Read the letter once for content, once purely for typos, separately, since reading for both at once lets errors slip past.
2. Confirm the company name and hiring manager's name are both correct, checked against the actual job ad or LinkedIn, not assumed from a previous application.
3. Check that at least one sentence couldn't be copied unchanged into a letter for a different company. If every sentence could, the letter isn't tailored yet.
4. Verify the email address in your signature or application profile reads as professional. This takes thirty seconds and removes one of the most-cited rejection reasons entirely.
5. Count your paragraphs. Four to five short ones, roughly half a page, matches what the largest share of recruiters say they prefer.

Common questions

What is the single biggest cover letter mistake?

According to the largest recent recruiter survey on this specific question, lying or exaggerating an achievement is the most-cited reason for rejection, at 76%, ahead of formatting and customization issues. All three sit close together, which means no one mistake on this list is safe to ignore in favor of fixing just one.

Do recruiters actually read cover letters, or is this outdated advice?

Yes, according to the same 2024 Zety survey, 83% of surveyed recruiters report reading cover letters, and 87% call them essential to deciding who gets an interview. The idea that cover letters are a formality nobody reads doesn't match what recruiters themselves report doing.

How long should a cover letter be?

Recruiter preference splits across roughly half a page (49%), a full page (26%), and a few sentences (25%), with half a page the single most common preference. Following a specific length instruction in the job ad or application portal takes priority over this general default.

What's the difference between a cover letter and a resume?

A resume lists your experience, skills, and achievements in a structured, scannable format. A cover letter is a short, written narrative that connects specific parts of that experience directly to one particular role, in prose rather than bullet points, and is the place to explain context a resume's format doesn't easily hold, like a career change or what specifically drew you to this job.

Is a generic cover letter better than no cover letter at all?

Usually not, given how often recruiters cite a lack of customization as a specific rejection reason. A cover letter that reads as copied-and-pasted can do more harm than skipping one entirely in a process that doesn't strictly require it, since it signals the same lack of effort a recruiter would otherwise have no direct evidence of.

Does an unprofessional email address really affect whether I get hired?

It's cited specifically by 61% of recruiters surveyed as a reason for rejecting application materials, which is a higher number than many job seekers would guess for what feels like a minor detail. Since fixing it takes minutes and removes the issue entirely, it's one of the easiest items on this list to resolve.

Where ResumeProofed fits, and where it doesn't

ResumeProofed doesn't proofread a cover letter you've already written elsewhere, and if what you need right now is a line-by-line check against the mistakes above, that's a manual read-through, not something to outsource. What it does instead is generate the cover letter from the start using only confirmed facts about your career, built around the specific job ad's language rather than a reused template, which heads off the customization and exaggeration mistakes before they have a chance to appear in a first draft.

Try ResumeProofed free: two tailored applications on the house, no card required.