What Is ATS? How Applicant Tracking Systems Really Work

ATS in Plain English

An Applicant Tracking System (ATS) is software that companies use to manage job applications. When you submit your CV through a company's careers page or a job board like Indeed, Reed, or Totaljobs, it almost always goes into an ATS before any human reads it. The software collects, organises, parses, and ranks applications — giving recruiters a shortlist of the most relevant candidates rather than forcing them to read every CV manually.

In the UK, ATS usage is near-universal among large employers and increasingly common among SMEs. If a company receives more than 50 applications per role — and many receive hundreds — an ATS is how they manage the volume.

The Most Common ATS Platforms in the UK

You have probably already interacted with several of these systems without realising it:

• Workday — Used by many FTSE 100 companies, banks, and large corporate employers.
• Oracle Taleo — Common in enterprise and public sector organisations.
• Greenhouse — Popular with tech companies and scale-ups.
• Lever — Favoured by mid-sized technology and SaaS businesses.
• SmartRecruiters — Widely used across retail and hospitality.
• Tribepad — A UK-built ATS used by NHS Trusts, local authorities, and large public sector employers.
• iCIMS — Common in financial services and professional services firms.

Each platform works slightly differently, but the core mechanics are the same. If your CV is optimised for ATS in general, it will perform well across all of them.

How ATS Processes Your CV: Step by Step

1. Parsing

The moment you upload your CV, the ATS parser extracts text from the file and attempts to map it to structured data fields: your name, email, phone number, work history (with dates, job titles, and companies), education, and skills. The parser reads from top to bottom, left to right, following the document structure.

If your CV uses tables, columns, text boxes, headers/footers, or embedded images, the parser may misread the order, skip sections entirely, or jumble your information. This is why formatting matters so much — a beautifully designed CV that the parser cannot read is functionally invisible.

2. Keyword Matching

Once the text is extracted, the ATS compares it against the job description. It looks for matches on specific terms: job titles, technical skills, software platforms, certifications, qualifications, and industry terminology. Some systems look for exact matches only; others use synonym matching (e.g., recognising that "financial modelling" and "financial analysis" are related).

The more keywords from the job description that appear naturally in your CV, the higher your relevance score. This is not about gaming the system — it is about ensuring your CV uses the same language the employer is using to describe the role.

3. Ranking and Filtering

After parsing and keyword analysis, the ATS assigns each application a relevance score or ranking. Recruiters can then sort candidates by score, filter by specific criteria (location, years of experience, qualifications), and focus their attention on the top-ranked applicants.

Some systems use simple percentage-based matching. Others, particularly newer platforms, use more sophisticated algorithms that consider keyword density, contextual usage, and even the recency of relevant experience. But the core principle is always the same: the closer your CV's language matches the job description, the higher you rank.

What Makes a CV ATS-Friendly?

Based on how these systems actually work, here is what you need to get right:

• File format: Submit a .docx or a text-based PDF. Avoid image-based PDFs (scanned documents), Canva exports, and InDesign files.
• Layout: Single column, no tables, no text boxes, no graphics. A straightforward top-to-bottom structure.
• Section headings: Use standard labels the parser expects: "Work Experience," "Education," "Skills," "Certifications." Avoid creative alternatives like "My Journey" or "Toolkit."
• Contact details: Place them in the body of the document, not in a header or footer.
• Fonts: Standard fonts like Arial, Calibri, or Garamond. Decorative fonts can cause character encoding issues.
• Keywords: Mirror the language of the job description. If they say "programme management," use that phrase, not "project oversight." Include both the full term and common abbreviations where appropriate (e.g., "Search Engine Optimisation (SEO)").
• Dates: Use a consistent format — "Jan 2023 – Present" or "January 2023 – Present" — so the parser can correctly calculate your tenure.

Common Myths About ATS

• "ATS rejects 75% of CVs automatically." This statistic is widely quoted but misleading. ATS does not typically reject applications outright — it ranks them. However, a low-ranking CV is unlikely to be seen by a recruiter, which has the same practical effect.
• "You can trick ATS with white text keywords." This technique (hiding keywords in white text) worked a decade ago. Modern systems detect it easily, and some flag it as attempted manipulation. Do not do it.
• "ATS cannot read PDFs." Most modern ATS platforms parse text-based PDFs without issue. The problem is with image-based PDFs and heavily designed PDF layouts. A clean, well-structured PDF is fine.
• "You need a special ATS template." You do not need a proprietary template. You need a clean, single-column layout with standard headings and no graphics. Any word processor can produce this.

How to Check Whether Your CV Passes ATS

There is a simple test you can do yourself. Open your CV as a PDF, select all the text (Ctrl+A), copy it (Ctrl+C), and paste it into a plain text editor like Notepad. If the text appears in the correct order, with all sections intact and readable, the ATS parser should have no trouble either. If the text is jumbled, sections are missing, or it looks garbled, your formatting needs work.

Automate the Optimisation

Manually checking and adjusting your CV for every application is doable but tedious. The AI CV Builder automates the entire process — parsing your existing CV, matching it against the job description, rewriting your content to include the right keywords, and outputting a clean, ATS-optimised document. It takes under a minute and ensures your CV performs well across all major ATS platforms used by UK employers.

Related Reading

• How to Pass ATS: A Complete Guide
• Best CV Format for the UK Job Market
• DevOps Engineer CV Template
• Cyber Security CV Template