7 Resume Mistakes That Get You Rejected by ATS (And How to Fix Them)

Before a human ever reads your resume, it passes through an Applicant Tracking System. ATS software parses your resume into structured fields: name, contact info, work history, skills, education. If the parser fails or the extracted data does not match the job's requirements, your resume gets filtered out automatically.

This is not theoretical. Studies estimate that 70-75% of resumes are rejected by ATS before reaching a recruiter. Many of those rejections are not about qualifications. They are about formatting.

Here are the 7 most common mistakes and how to fix them.

Mistake 1: Using a creative or multi-column layout

The problem: ATS parsers read documents top-to-bottom, left-to-right. Multi-column layouts, sidebars, text boxes, and creative arrangements confuse parsers. Your skills section in the left column might get merged with your job titles in the right column, producing gibberish.

The fix: Use a single-column layout. Simple section headings (Experience, Education, Skills) in bold. No text boxes, no tables, no columns. Boring-looking resumes parse perfectly, and that is what matters at this stage.

Mistake 2: Submitting as PDF when the system wants .docx (or vice versa)

The problem: Some older ATS systems parse .docx better than PDF, and some newer ones prefer PDF. There is no universal standard. If the listing says "upload your resume" with no format guidance, you are guessing.

The fix: Have both formats ready. If the application form specifies a format, use it. If it does not specify, PDF is generally safer for modern systems (Greenhouse, Lever, Ashby). For older systems (Taleo, iCIMS), .docx can parse more reliably. When in doubt, submit PDF.

Mistake 3: Missing keywords from the job listing

The problem: ATS systems score resumes by keyword match against the job description. If the listing says "React" and your resume says "ReactJS," some parsers treat those as different keywords. If the listing says "CI/CD" and your resume says "continuous integration," you might not get matched.

The fix: Mirror the exact terminology from the job listing. Read the listing carefully and use the same phrases. If they say "PostgreSQL," say "PostgreSQL" (not "Postgres" or "SQL databases"). If they say "Agile methodology," use that exact phrase somewhere in your resume.

This does not mean keyword stuffing. It means using precise, matching terminology for skills you actually have.

Mistake 4: Burying important information below the fold

The problem: Some ATS systems and many recruiters only scan the top third of a resume. If your most relevant experience or skills are on page 2, they might never be seen.

The fix: Put a skills summary section near the top, right after your contact information. List your most relevant technical skills explicitly. Then list your most recent and relevant role first in your experience section. Everything above the fold should scream "I am qualified for this role."

Mistake 5: Using headers and footers for contact information

The problem: Many ATS parsers ignore headers and footers entirely. If your name, email, and phone number are in the header, the system might parse your resume as anonymous, making it impossible to contact you.

The fix: Put your name and contact information in the main body of the document, at the very top. Not in a header. Not in a footer. In the regular document body.

Mistake 6: Listing responsibilities instead of achievements

The problem: This one affects human reviewers more than ATS, but it is critical. "Responsible for building REST APIs" tells a reviewer nothing about your impact. Every backend engineer builds REST APIs. So what?

The fix: Quantify everything possible. "Built REST APIs serving 2M daily requests with 99.9% uptime" is dramatically more compelling. "Reduced API response time by 40% by implementing Redis caching" shows both what you did and why it mattered. Numbers make your resume stand out in a stack of generic descriptions.

If you do not have exact numbers, estimate reasonably. "Served approximately 500K users" is better than "served many users."

Mistake 7: Including irrelevant experience without connecting it

The problem: If you are applying for a software engineering role and your resume includes 3 years of experience as a barista with no connection to tech, it dilutes your profile. ATS keyword matching scores your entire resume, and irrelevant experience adds noise without adding signal.

The fix: Either remove irrelevant roles or reframe them. "Managed inventory tracking system and trained 12 staff on POS software" is more relevant to a tech role than "served coffee and handled cash register." If a past role genuinely has no tech connection and you have enough relevant experience to fill your resume, leave it off.

Testing your resume

Before you submit, test your resume through a parser. Copy-paste your PDF into a plain text editor. If the result is readable and all your sections are in the right order, ATS will probably parse it correctly. If it is scrambled, fix the formatting.

OpteroAI includes a resume scoring tool that checks for these exact issues. Upload your resume at /tools/resume-score and get specific feedback on what to fix before you apply.

The goal is simple: get past the machine so you can talk to a human. None of these fixes require lying or exaggerating. They just require presenting your real qualifications in a format that automated systems can actually read.