What a Cover Letter Is Actually For

Most bad cover letters are bad for the same reason: the writer doesn’t know what the document is supposed to do. Given no brief, people default to one of two failure modes.

Failure mode one: the resume in prose. Three paragraphs restating the work history that’s attached to the same email. The reader has that information. Reading it twice, less efficiently, is not a service.

Failure mode two: the declaration of feeling. “I have long admired your company’s innovative approach and would be thrilled to contribute to your continued success.” This is what people write when they have nothing specific to say, and readers know that, so it’s discounted before it’s finished.

Both are attempts to fill a page without a brief. So let’s give you the brief.

The job only this document can do

A resume is a record. It’s structured, chronological, and impersonal by design — a list of what happened, in reverse order, with no argument attached.

What it cannot do is connect your specific experience to their specific problem. A resume can say you spent two years consolidating regional reporting. It can’t say “I noticed your posting mentions consolidating reporting across regional teams, which is exactly the thing I spent 2023 doing, and here’s the part that turned out to be hard about it.”

That’s the cover letter’s job. Not more information — the connection between the information and their situation. You’re doing a small piece of work the reader would otherwise have to do themselves, and doing it better than they could, because you know your own history and they don’t.

Everything else people put in cover letters is filler around that.

What makes it work

One specific thing from the posting. Not “your requirements align well with my background,” which is a claim about alignment rather than a demonstration of it. Name the actual requirement, and say what you’ve done that maps to it.

One thing about your experience they can’t see in the resume. The context, the constraint, the reason a line on your resume is more impressive than it sounds. “The reporting consolidation was the interesting part because the three regions had incompatible definitions of a ‘closed’ order, so most of the work was getting four teams to agree on one definition before any of the technical work could start.” That sentence tells a reader more about your capability than any bullet point can.

Something that shows you thought about them for more than a minute. A genuine question about the role. An observation about the problem they seem to be hiring against. Evidence that you read past the first paragraph of the posting.

A reason you’re applying that isn’t insulting to both of you. This is where honesty helps. “This role is a step up in scope and the work is close to what I already do well” is a real reason and a perfectly good one. “I’ve been passionate about your mission since childhood” is not, and the interviewer’s follow-up question will establish that.

What to leave out

Your entire work history. One or two experiences, chosen because they’re relevant here. Not a tour.

Manufactured enthusiasm. If you have no strong feelings about the company — which is extremely normal, particularly for a business-to-business firm you’d never heard of before the posting — don’t fake it. Write about the work instead. The work is a legitimate reason to want a job, and writing about it convincingly is far more persuasive than admiration you’ll have to defend later.

Apologies and hedges. “Although I don’t have direct experience in…” Never introduce a doubt the reader hadn’t reached. If there’s a genuine gap, address it once, positively, and move on.

“I believe I would be a great fit.” You can’t assert this into existence. Show the fit and let them conclude it.

Anything about what the job would do for you. Growth, opportunity, the chance to develop. Real motivations, wrong document. The letter is about what you’d bring.

Does anyone read it?

Honestly: it varies enormously, and anyone who gives you a confident percentage is making it up.

Some hiring managers read every letter and weight them heavily — particularly at smaller companies, in writing-adjacent roles, and for anything senior. Some large organisations discard them by policy or never surface them to the person deciding. In some countries a letter is a mandatory part of an application; in others it’s faintly unusual and a short email is the norm.

Three practical implications:

1. If a form has an optional cover letter field, fill it in. The downside is ten minutes. The upside is that you’re one of the few applicants who did, in front of a reader who may well be looking for exactly that.
2. Front-load it. If it gets skimmed, it gets skimmed from the top. Your best material goes in the first two sentences, not paragraph three.
3. Never rely on it. The resume has to stand alone, because sometimes it will.

The length question

Shorter than you think. Around 250–350 words, three or four short paragraphs, fitting comfortably on a screen without scrolling.

A full page of dense text signals that you couldn’t identify what mattered. A tight three paragraphs signals judgement — and judgement is a large part of what’s being assessed.

For an email-body application, shorter still: 150–200 words. Nobody scrolls an email from a stranger.

The reframe that makes it easy

Stop thinking of it as a formal letter, which is where the stiffness comes from, and start thinking of it as the email you’d send a colleague who asked why you were interested in a job.

You’d say: here’s what caught my eye, here’s the thing I’ve done that’s closest to it, here’s what I’d want to know more about. Three sentences, natural register, no “I am writing to express.”

That’s the document. The formality is optional; the substance is not. Once you know the letter has one job — connect your specific experience to their specific problem — the blank page stops being intimidating, because there’s now a question to answer rather than a form to fill.

The four-paragraph shape that implements this is in the four-paragraph cover letter.