Career

Job description vs person specification: what each document does

Rive News Research Desk

Published October 28, 2026 · 9 min read

By Rive News / Research desk | Rive News / Published October 28, 2026 at 9:00 AM PKT

Key takeaways

A job description describes the role: its purpose, duties, reporting line and working conditions.
A person specification describes the person: the qualifications, skills, experience and attributes needed to do the role well.
Employers use the two together, with the specification as the scoring sheet for shortlisting and interviews.

A resume on a clipboard beside a laptop on a desk

A job description and a person specification answer different questions about the same vacancy. Photograph: resume and laptop on a desk

Image Credits: Pexels

Job adverts often blur two documents into one long list, and candidates pay the price in confusion. A job description describes the job.

A person specification describes the person the employer hopes to hire. Knowing which is which helps applicants judge their fit and helps employers hire fairly.

This article explains the difference between a job description and a person specification, including what each document contains, how each is used at each hiring stage, and the mistakes that turn both into trouble.

The job description: what the role involves

A job description is a written statement of a specific job. NI Business Info, Northern Ireland's official business advice service, states that it outlines the overall purpose of a role and the main tasks carried out by the job holder. A typical description includes the job title, the main duties and purpose, information about the company, and the job location.

The description also sets the role in context. It states who the job holder reports to, how the role relates to other roles, and what working conditions apply. TAFE NSW training material for recruitment staff describes a job description as a detailed statement of the tasks, duties and responsibilities of a job, covering the work actually done rather than the person doing it.

Good descriptions focus on outcomes as well as tasks. Listing "answer customer emails" says less than "resolve customer queries within one working day." Outcomes tell candidates what success looks like and give managers a basis for later performance reviews.

The person specification: who can do it well

A person specification is a concise profile of the person who would best match the job. CIPD-linked study material quoted by Studypool defines it as spelling out which attributes are essential and which are desirable, so candidates can judge whether to apply and employers gain a benchmark for assessment.

DavidsonMorris, an employment law firm, describes the same split: a person specification outlines the essential and desirable qualifications, skills, experience and personal attributes required for a role. It helps employers identify suitable candidates and keeps shortlisting consistent.

Typical contents include qualifications, work experience, technical skills, aptitudes such as numeracy or communication, and personal qualities such as flexibility or willingness to work shifts. ITSA People, a recruitment consultancy, advises distinguishing attainments, aptitudes and personal qualities, and warns against vague criteria such as "excellent communication skills" without saying what that means in practice.

The core difference in one line

The job description answers "what will this person do each day?" The person specification answers "what kind of person do we need to do this job well?" Sprintlaw UK puts it exactly that way in its employer guide, and the distinction drives everything else.

Confusing the two causes real problems. A description padded with person requirements ("must be a team player with five years' experience") hides the actual duties.

A specification padded with duties ("will manage the office rota") gives shortlisters nothing to score. Each document does one job, and each does it better alone.

Essential versus desirable criteria

The most useful feature of a person specification is the essential-desirable split. Essential criteria are the minimum needed to do the job well. A candidate who lacks one should not be shortlisted, however strong the rest of their application.

Desirable criteria allow better or faster performance but are not required on day one. A desirable language skill, an extra qualification or familiarity with a particular system can separate two appointable candidates without excluding capable people who lack it.

ITSA People advises keeping criteria realistic and avoiding higher standards than necessary. Inflated criteria shrink the applicant pool, exclude good candidates and can look discriminatory if they screen out a protected group without justification. Each criterion should be measurable and relevant to the role, a point DavidsonMorris stresses.

How employers use each document

Both documents start from job analysis, the process of collecting and setting out information about a job. Armstrong and Taylor, cited in CIPD-linked study material, define job analysis as gathering information that provides the basis for a job description and data for recruitment, training, job evaluation and performance management.

The job description then shapes the advert. It tells applicants what the work involves, where it sits and what it pays in broad terms. The person specification shapes the shortlisting grid, with each criterion scored so that every applicant faces the same test.

At interview, the specification shapes the questions. Each essential criterion deserves at least one question or exercise that tests it directly. After appointment, the job description becomes the reference for probation and appraisal, since it records what the role was agreed to involve.

Legal standing and fairness

Neither document is a legal requirement in the UK, according to both NI Business Info and Sprintlaw UK. Employers are not forced by law to produce either one for every vacancy. Both sources still recommend them strongly, and the reasons are practical rather than formal.

A clear person specification helps an employer prove a decision was fair if it is challenged. Sprintlaw UK notes that Acas and the Equality and Human Rights Commission recommend clear criteria, and that a written specification reduces unconscious bias by keeping attention on who can do the job rather than who the panel clicks with.

NI Business Info adds that a specification helps ensure all applicants are scrutinised systematically using the same criteria, so a shortlist can be justified on objective grounds. Criteria must still avoid discrimination: requirements that disadvantage a group need a genuine job-related reason, and wording should stay inclusive throughout.

Common mistakes with job descriptions

The classic mistake is copying an old description without checking it. Roles drift over time, and a description written five years ago may describe a job that no longer exists. Candidates then join expecting one role and find another, which damages trust and retention.

Another mistake is listing every task anyone in the team has ever done. A description with 40 duties tells candidates nothing about priorities. Five to eight main duties, ordered by importance, give a clearer picture than an exhaustive catalogue.

Vague language causes a third problem. Phrases such as "support the team" or "handle various tasks" hide the real work. Specific verbs and outcomes fix this: "prepare the monthly sales report" beats "assist with reporting" every time.

A desk with a resume, coffee and laptop seen from above

A clear description of duties plus a scored specification gives both sides a fair basis for decisions. Photograph: desk with resume and laptop

Image Credits: Pexels

Common mistakes with person specifications

The mirror mistake is demanding everything at once. A specification that asks for a degree, ten years' experience, three languages and a driving licence for a junior office role will deter good applicants and invite challenge. ITSA People advises specifying the type of experience needed without always stipulating its length.

Subjective criteria cause trouble too. "Good sense of humour," "dynamic personality" and "cultural fit" cannot be scored consistently, and they open the door to bias. If a quality matters, the specification should say how it shows up at work, such as "explains technical faults to non-technical customers calmly.

A further mistake is never reviewing the specification. Roles change, technology changes and the labour market changes. DavidsonMorris recommends regular reviews so criteria stay relevant to the evolving needs of the role and the organisation.

How candidates should read both documents

Candidates should read the job description first and ask whether the daily work appeals to them. Duties, reporting line, location and working pattern matter more than the employer's praise for its own culture. If the duties do not fit, no specification match will fix that.

Then they should score themselves against the person specification honestly. Essential criteria deserve direct evidence in the application, with one example per criterion. Desirable criteria are worth mentioning but should not dominate the application at the expense of essentials.

Gaps in desirable criteria should not stop an application. Employers list desirable qualities as preferences, and a strong match on essentials plus relevant evidence often wins. Gaps in essential criteria are different, and candidates should weigh them seriously before applying.

Frequently asked questions

Is a person specification the same as a job advert?

No. An advert is a shortened, public version of both documents. The full description and specification sit behind it and guide shortlisting.

Must employers publish the person specification?

No law requires it in the UK, but publishing it helps candidates self-select and helps employers defend their decisions. Many employers include it in the application pack.

What counts as an essential criterion?

Anything the role cannot be done well without. If a new hire could learn it quickly on the job, it belongs under desirable, not essential.

Can a job description change after hiring?

Yes, roles evolve, but changes should be discussed and recorded rather than imposed silently. The description is the agreed record of the role.

Who writes these documents?

Usually the hiring manager drafts them with human resources support. Input from the current role holder, where one exists, makes both documents far more accurate.

The bottom line

A job description and a person specification are partners, not rivals. One describes the work, the other describes the worker, and together they give hiring decisions a fair, consistent basis. Employers who write both carefully get better applicants, cleaner shortlists and decisions they can defend.

Candidates who read both carefully get something equally valuable: an honest picture of the job and a clear sense of whether they fit it. That clarity saves both sides time, and it is the real purpose of the pair.

Tags: job description, person specification, recruitment

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