5 Common Cover Letter Mistakes and How to Avoid Them

Even strong candidates get rejected because of preventable cover letter mistakes. Here are the five most common errors — and exactly how to fix them.

Mistake #1: Starting with "To Whom It May Concern"

This dated phrase signals laziness. In 2026, you can almost always find the hiring manager's name with 5 minutes of LinkedIn research.

The fix: Search for "[Company] [Department] Manager" on LinkedIn. If you truly can't find a name, "Dear Hiring Manager" is acceptable. Better yet, address it to the department head by title: "Dear Engineering Team Lead."

ATS impact: Some modern ATS systems check for personalization. Generic salutations can lower your personalization score.

Mistake #2: Repeating Your Resume

Recruiters read your resume first. If your cover letter just rehashes the same information, you've wasted their time — and yours.

The fix: Pick 2-3 achievements from your resume and tell the story behind them. What problem did you solve? How did you approach it? What was the impact? Add context, not repetition.

Mistake #3: Forgetting to Customize for Each Application

Using a generic cover letter for every application is the fastest way to the rejection pile. Recruiters can spot a template in seconds.

The fix: For each application, customize at least:

• The company name (obviously)
• One specific reference to the company's product, mission, or recent news
• Why this specific role interests you (not just "I want to work at a great company")

Mistake #4: Grammar and Spelling Errors

A single typo can kill your chances — especially for roles requiring attention to detail. "Proffesional" is not professional.

The fix: Three-pass proofreading:

1. Read it aloud (you'll catch awkward phrasing)
2. Run it through a grammar checker (Grammarly, Hemingway, or built-in tools)
3. Have someone else read it (fresh eyes catch what yours miss)

Mistake #5: Not Optimizing for ATS

In 2026, this is the silent killer. You wrote a beautiful, poetic cover letter — and the ATS scored it 45/100 because it lacked keywords, used unusual formatting, or was too short.

The fix: Run your cover letter through an ATS analysis tool before submitting. ATSLetter provides instant ATS scoring across four dimensions: keyword match, format compatibility, writing quality, and personalization. Fix the flagged issues before hitting send.

Bonus: The One Mistake No One Talks About

Not sending one at all. According to a 2026 CareerBuilder survey, 45% of applicants skip the cover letter entirely. That means simply including a cover letter immediately puts you ahead of nearly half the applicant pool. Don't leave free advantage on the table.