What Is a Cover Letter and When Do You Need One?

Here's the contradiction sitting at the top of every cover letter debate:

Vendor-funded surveys (Zety, 2025) say 83% of recruiters read cover letters. A Glassdoor/Fishbowl poll of 13,000+ professionals says only 10% of hiring managers think they're necessary, and 58% find them outright redundant.

Both claims are about the same document. They can't both be right. Let's figure out what's actually going on.

What Is a Cover Letter?

A cover letter is a short introductory document you send alongside your resume. Its job is to motivate the hiring manager to actually read your resume. It's not a summary of your resume, it's an argument for why this specific job at this specific company fits this specific candidate. One page, focused on what you can do for them.

That's the Glassdoor definition and it captures the core function well: the cover letter leads the reader to want to know more about you. The Ford School of Public Policy at University of Michigan frames it as a WIIFM problem, "what's in it for me," where the "me" is the employer, not you. Every line should answer: why does this help them?

That's what separates a functional cover letter from the kind that gets ignored immediately.

The Reading Rate Problem: Vendor Data vs Independent Data

Most statistics about cover letters come from resume-building software companies. This matters.

What vendor surveys say:

Zety (2025) (note: Zety is a resume builder, so they have a financial interest in cover letters being important): 83% of recruiters read cover letters; 89% expect one.
ResumeLab (2020) (also a resume product, n=200 recruiters): 83% said cover letters are important; 77% prefer candidates who send them.

Both numbers are strikingly similar and both come from companies whose revenue depends on people believing cover letters are essential. That doesn't make them wrong, but it should make you pause.

What independent data says:

Glassdoor/Fishbowl (2022), surveying 13,000+ working professionals (not a resume vendor): only 10% of hiring managers called cover letters necessary; 58% called them redundant.
A LinkedIn hiring manager who read 1,000+ cover letters estimates that roughly 50% of recruiters read them and 50% don't, depending on the company, the role, and how slammed the recruiter is.

The honest answer: cover letter read rates probably sit somewhere between 10% and 50%, depending heavily on context. Not 83%.

When It Gets Read vs When It Gets Ignored

Context matters more than the document itself. Here's what actually determines whether anyone opens your cover letter:

More likely to be read:

You're applying through a direct referral to a specific hiring manager
The job posting asks for a cover letter (optional but you submit a tailored one anyway)
The role itself tests communication: advertising, PR, journalism, content, executive writing
Senior, executive, or academic roles where fit and judgment are being assessed
Non-profits, where culture and mission alignment are taken seriously

Almost certainly ignored:

High-volume ATS portals at large companies (your application may not reach a human before screening)
You submitted a generic letter with the company name swapped out
The job posting doesn't ask for one and the recruiter is handling 200+ applications
Automated screening filters out your application before anyone reads anything

The ResumeWorded breakdown (flag: ResumeWorded is a resume service, so take the framing with context) is consistent with what independent data suggests: the gap between "read" and "ignored" is determined almost entirely by application volume and role type, not by whether the cover letter is well-written.

If a recruiter is managing 300 applications for one role, they are not reading 300 cover letters. That's not cynicism, that's math.

Are Cover Letters Less Important in 2025 Than They Were Five Years Ago?

Yes, probably. A few things have pushed in that direction:

AI-generated cover letters normalized mediocrity. When everyone can produce a polished-sounding letter in 30 seconds, a polished-sounding letter stops being a signal. Recruiters know this. Generic AI output looks like generic AI output, and it's made the baseline lower, not higher.

ATS filtering means cover letters often don't reach human eyes at all. If your resume doesn't clear keyword filters, nothing else gets read. We covered this in detail in how ATS actually works, but the short version: the cover letter is downstream of a parsing and filtering step that most applicants don't pass.

Recruiter attention has gotten shorter, not longer. The Jobvite 2025 Job Seeker Nation Report (survey by Zogby Analytics, n=1,500+) found that only 26% of recruiters consider cover letters "very important" at the initial screening stage. That number has dropped from similar surveys five years prior.

None of this means cover letters are dead. It means the average cover letter, sent to an ATS portal at a mid-sized company, has a low probability of changing anything.

When a Cover Letter Is Actually Worth Writing

There are four situations where writing one is genuinely worth the time:

1. Career change. Your resume shows a trajectory that doesn't obviously lead to this role. The cover letter is the only place to explain the pivot directly and preemptively answer the recruiter's obvious question: why are you applying for this?

2. Employment gaps. Resumes document what happened; they can't explain why. A gap from caring for a family member, a health situation, or a deliberate sabbatical reads differently when there's context. The cover letter provides that context without you looking like you're hiding something.

3. Direct or email applications. If you're sending an application directly to a hiring manager or through a personal referral, a human will read what you send. This is the highest-ROI situation for a cover letter. The ATS layer is removed. Write a real one.

4. Roles where writing ability is the job. If you're applying for anything in communications, content, marketing, or executive roles where written judgment matters, not sending a cover letter is itself a signal. A weak cover letter is worse than none, but a strong one in these contexts is weighted heavily.

For everything else, especially high-volume applications to large company portals, your time is better spent on the resume itself. A well-tailored resume that clears ATS and reads well to a human is higher leverage than a cover letter that may not be opened. If you're not sure how to tailor your resume properly, this guide on matching your resume to the job description covers the method.

The Golden Rule

If you're going to write a cover letter, make it specific to this role at this company, or don't write it at all.

Generic letters actively hurt you. They signal that you couldn't be bothered to spend 20 minutes on this application, which makes the recruiter wonder what your work ethic looks like on the job. A missing cover letter is neutral. A lazy one is negative.

The specifics that make a cover letter worth reading: one concrete reason you want this role (not "I've always been passionate about"), one direct connection between your experience and a stated need in the job posting, and a clear ask. That's it. Under 300 words. No throat-clearing.

If you're not sure why your applications aren't getting responses in the first place, a cover letter may not be the lever. This breakdown of why resumes get no callbacks starts at the more upstream problems.

On the resume side: if you're applying to multiple roles and want tailoring that mirrors each job description's vocabulary without rewriting everything manually, BulkResumes handles that. The cover letter is a separate problem you still need to solve yourself, but the resume part can scale.

For when you do write one, this guide on cover letters that get read covers what actually works at the structural level.

The Short Version

A cover letter is a one-page argument for why you fit this role, focused on what you offer the employer, not what you want
Vendor surveys (83% read rate) come from resume-builder companies with a financial interest in that number; independent data (Glassdoor/Fishbowl, n=13,000+) puts it at 10% necessary, 58% redundant
Read rates are context-dependent: direct applications get read, ATS portal mass applications usually don't
Cover letters are less important in 2025 than five years ago (AI saturation, ATS filtering, declining recruiter attention)
The four situations where one is worth writing: career change, employment gaps, direct/email applications, writing-dependent roles
Generic cover letters are worse than no cover letter; tailored and specific is the only version worth sending