The Complete ATS Guide: How Applicant Tracking Systems Work

If your resume has been submitted to a handful of job applications and come back with nothing but silence, the problem might not be your experiences or skills. It might be that an ATS resume checker never let a human being see your resume at all.

Applicant Tracking Systems (ATS) now sit in front of the vast majority of hiring processes, from small businesses to global corporations. They scan, parse and score every resume before a recruiter opens a single one. A strong candidate with a poorly formatted resume can be filtered out in seconds, while a weaker candidate with a clean, ATS-compliant CV sails through to the interview pile. That gap is exactly what this guide is here to close.

Below, you will find a complete breakdown of how ATS software actually works, the 12 rules every resume needs to follow, the formatting mistakes that quietly sink good applications, and practical ways to check your own resume before you send it out again.

Quick answer: what does an ATS resume checker actually do?

An ATS resume checker analyses your CV the same way an Applicant Tracking System does: it extracts your text, checks your formatting against parsing rules, compares your content against the keywords in a job description, and returns a score showing how likely your resume is to pass automated screening. A good checker also tells you exactly what to fix, not just what went wrong.

Curious how your own CV stacks up? Run your CV through the free ATS Checker and see your score in seconds.

What is an ATS, and why is your resume being rejected before a human sees it?

An Applicant Tracking System (ATS) is software that employers use to collect, sort and filter job applications before a recruiter reviews them. Instead of a person opening every CV that arrives for a role, the ATS reads each document, extracts the text into a structured record, and ranks or filters candidates based on how well that record matches the job requirements.

The scale of modern hiring makes this almost unavoidable. A single popular job posting can attract hundreds of applications within days, and no recruitment team can manually review all of them. An ATS solves that volume problem, but it introduces a new one for candidates: the system is only as good as its ability to read your document correctly, and most resumes are not built with that in mind.

This is where good applications quietly disappear. A resume built in a visually creative layout, with columns, graphics or an unusual font, can look excellent on screen and still come out of the ATS as a jumbled, incomplete record. Job titles attach to the wrong dates, skills sections vanish, and contact details go missing. The recruiter never sees a “bad candidate”; they simply never see an accurate version of you at all.

Rejection at this stage has nothing to do with your qualifications, skills or experiences. It comes down to whether the software could read your document the way you intended it to be read. That is precisely why a resume built with our ATS Resume/CV Builder is designed around parsing rules first and visual styling second, the opposite order to most general-purpose design tools.

For the full breakdown of exactly where these failures happen, see our article on what an ATS is and why your resume is being rejected before a human sees it.

The 12 ATS rules every job seeker should know

Every ATS parses documents slightly differently, but the resumes that consistently pass screening all follow the same underlying rules. Treat this list as non-negotiable rather than optional advice.

1. Use a single-column layout. ATS software reads top to bottom, left to right. A two-column layout causes it to read halfway down one column, jump to the other, then return; mixing job titles, dates and education together.
2. Avoid tables for layout. Tables built for design purposes are frequently skipped entirely by parsers, taking whatever content sits inside them out of the picture.
3. Skip text boxes and floating frames. Content placed in a floating box can be invisible to the software, even though it looks perfectly normal on screen.
4. Leave out decorative images. Photos, icons and graphics are ignored by ATS parsers and add visual noise without adding readable information.
5. Do not use icons as bullet points. Icon-based bullets are commonly misread as blank characters or symbols, quietly damaging your keyword density.
6. Skip progress bars and skill ratings. A five-star skill graphic reads as nothing to an ATS. Replace it with the actual skill, written out.
7. Stick to standard, widely embedded fonts. Arial, Helvetica, Calibri, Times New Roman, Georgia, Garamond and Cambria are all safe. Unusual fonts risk character substitution during parsing.
8. Keep body text at 10pt minimum, 11pt recommended. Smaller text is more likely to be missed, particularly by scanners relying on image-based extraction.
9. Use standard section headings. “Work Experience,” “Education” and “Skills” are recognised instantly. Creative alternatives such as “My Journey” are often not categorised correctly.
10. Keep contact details out of the header and footer. Many ATS platforms do not read header or footer regions at all, which means your phone number and email can simply disappear.
11. Check your reading order matches your visual order. The underlying document structure should flow the same way a human eye would read it, top to bottom.
12. Leave a minimum of half an inch of margin on every side. Narrow margins increase the risk of text being cut off during parsing.

Every one of these rules exists for the same reason: to make sure the words you have written actually reach the system reading them. Our own free ATS resume checker tests your CV against all 12 automatically and shows you exactly which ones are failing.

For a deeper walkthrough of each rule with examples, read the 12 ATS rules every job seeker should know.

Ready to see where your own resume stands? Run your CV through the free ATS Checker; it takes less than a minute and shows your score straight away.

Why multi-column resumes fail ATS screening (and what to use instead)

Multi-column layouts are one of the single biggest causes of ATS failure, and they are also one of the most common design choices in free resume-building tools, because they look modern and make efficient use of page space.

The problem is entirely mechanical. Most parsers extract text in a linear stream based on the position of text blocks in the underlying document structure, not the way your eyes travel across the page. When a layout splits into a sidebar and a main column, the parser frequently reads a chunk of the main column, jumps into the sidebar, then jumps back, stitching together a document that bears little resemblance to the one you designed.

The practical result is that a job title from one role can attach to the dates from another. Skills sitting neatly in a sidebar can be dropped from the parsed record altogether. A contact detail placed in a decorative header block might never reach the system at all. Testing across free design tools has repeatedly shown ATS failure rates well above 70% specifically tied to multi-column and sidebar layouts.

The fix is straightforward: use a single-column, top-to-bottom structure for every section, with your name and contact details at the very top of the main body, not inside a header, footer or sidebar. This does not mean your resume has to look plain. Strong typography, clear section dividers and consistent spacing can still produce a polished, professional document without splitting the page into competing columns.

If you want a guaranteed starting point, our ATS Compliance Checklist Tool walks through every structural check, including this one, against your actual document. You can also read the full explanation in why multi-column resumes fail ATS screening (and what to use instead).

ATS-friendly fonts and formatting

Getting the structure right solves most of the problem, but formatting details matter just as much, particularly for anyone relying on an image-based or older ATS platform for parsing.

A quick way to sense-check formatting: if you copy your resume text and paste it into a plain text editor, everything should still make sense in the right order, with no missing sections and no jumbled dates. If it does not read cleanly there, an ATS will likely struggle with it too.

For the definitive breakdown of safe fonts, spacing and layout choices, see ATS-friendly fonts and formatting: the definitive list. You can also build directly onto a pre-formatted, ATS-verified layout using our ATS Resume/CV Builder, which removes the guesswork from every item in the table above.

How to beat applicant tracking systems

Passing the parsing test is only half the challenge. Once your resume is read correctly, most ATS platforms also score or rank it against the job description, which means content matters just as much as structure.

• Mirror the language of the job description, not just the skills. If the posting says “project management,” using only “managing projects” elsewhere in your resume can weaken your keyword match. Use the exact phrasing where it genuinely applies to your experience.
• Lead every bullet point with a strong action verb. Words such as “managed,” “delivered” or “reduced” are parsed as clear indicators of ownership and impact, unlike vague phrases such as “responsible for” or “helped with.”
• Quantify results wherever you can. Numbers, percentages and timeframes give both the ATS and the recruiter behind it something concrete to evaluate.
• Avoid keyword stuffing. Repeating a keyword unnaturally, or hiding it in white text, does not improve your score on any legitimate ATS and can actively work against you during human review.
• Tailor your resume for each application. A generic resume sent to fifty different roles will always match fewer keywords than one adjusted for each specific job description.
• Use both the acronym and the full term where relevant. If you have a certification or skill commonly referred to both ways — such as “Search Engine Optimisation (SEO)”, include both versions so you are captured either way the ATS is searching.
• Keep your job titles close to how the industry actually uses them. Wildly creative internal titles can fail to match standard role searches, even when the responsibilities are identical.

None of these tactics requires guesswork if you can see exactly which keywords your resume is missing. Our CV Review tool’s keyword gap analysis compares your resume against the top terms for your target role and shows precisely what to add without you having to fabricate experience you do not have.

To see nine further tactics in detail, read how to beat applicant tracking systems: 9 proven tactics.

ATS resume examples

Seeing the difference between a weak bullet point and a strong one is often the fastest way to understand what an ATS and the recruiter reading the output is actually looking for. Here are a few illustrative examples of the same experience, rewritten to pass both stages.

Before: Responsible for managing client accounts and handling customer queries.

After: Managed a portfolio of 40+ client accounts, resolving 95% of queries within 24 hours and improving renewal rate by 18% year-on-year.

Before: Helped with the marketing team on various campaigns.

After: Supported five marketing campaigns across social and email channels, contributing to a 22% increase in qualified leads over two quarters.

Before: Worked on improving internal processes.

After: Redesigned the internal onboarding process, cutting new-hire ramp-up time from six weeks to three.

Each “after” version follows the same pattern: a strong opening verb, a specific scope, and a measurable outcome. That structure gives an ATS clean, parseable content to score, and gives a recruiter an immediate sense of impact once they open the document.

For a wider set of examples across different roles and seniority levels, see ATS resume examples: 5 real resumes that passed and why.

Free vs paid ATS checkers: what’s actually worth paying for

Not every ATS check needs to be paid, but the free and paid tiers genuinely serve different purposes. Here is how they compare.

If you are applying for the first time or simply want a sanity check before you submit, the free tier is the right starting point. If you have already sent out several applications with no response, the full report is where the actual diagnosis and the fix happens.

Run your CV through the free ATS Checker to see which category your resume falls into.

Frequently asked questions

Explore our ATS compliance tools

Once you understand how ATS software reads your resume, the next step is testing your own document against it directly. These tools cover every stage, from a first free check through to a fully rebuilt, ATS-verified CV.

• ATS Resume/CV Builder: build a new resume from scratch on a template that is ATS-verified by design, so you never have to think about columns, tables or fonts again.
• Free ATS Resume Checker: upload your existing resume and get an instant compliance score plus your top three issues, at no cost.
• ATS Compliance Checklist Tool: run through every rule covered in this guide against your own document, one item at a time.

Explore related Landing Page for ATS Compliance to find the right starting point for where you are in the process.

Related articles

• What is an ATS and why is your resume being rejected before a human sees it?
• The 12 ATS rules every job seeker should know
• Why multi-column resumes fail ATS screening (and what to use instead)
• ATS-friendly fonts and formatting: the definitive list

Formatting rules and keyword tactics only tell you so much until you test them against your own document. If you take one action after reading this guide, make it this one: run your CV through the free ATS Checker and see exactly where you stand.