When a cover letter is read, and when it is not

The application types where a cover letter is read and weighted, the ones where it is never opened, and how to allocate your time accordingly.

The short answer: Cover letters are read in some application routes and never opened in others, and the difference is predictable enough to plan around. They matter most where a human owns the shortlist and the pool is small: direct applications to smaller employers, roles you are reaching for, internal moves, speculative approaches, and any application that came from a referral. They matter least in high-volume graduate schemes with structured application forms, agency-submitted applications, and roles where an assessment or test is the real first filter. Writing a careful letter for every application is not diligence — it is spending your best preparation hours where they cannot pay off.

Key points

Where a structured application form exists, the form is the screening instrument and the letter is usually an attachment nobody opens.
The smaller the employer and the smaller the applicant pool, the more likely one person reads everything you send.
A letter earns most when your resume raises an obvious question — a career change, a gap, a step down, an unusual route in.
Time saved by not writing letters where they do not count is better spent on research and evidence for the ones where they do.

Where a letter is genuinely read

The question is not whether cover letters work in the abstract. It is whether a person will open yours, and that depends on how the application arrived and how many others arrived with it.

Likelihood a letter is read, by application route
Route	Read?	Why
Direct application, small employer	Usually	One person owns the whole shortlist
Referral or internal move	Usually	Someone is already advocating and needs material
Speculative approach	Always — it is the application	There is no posting and no form
Mid-size employer, posted role	Sometimes	Depends on volume and on who screens
Large graduate scheme	Rarely	The structured form and tests are the filter
Agency submission	Rarely	The agency writes its own summary

The pattern is consistent: a letter is read wherever a named human owns the decision about you and has time to form a view. It is not read wherever the first filter is a process.

The four situations where it changes the outcome

Your resume raises a question. A gap, a career change, a step down in seniority, a move between countries. Left unexplained, the reader invents an explanation, and the invented one is rarely generous.
You are reaching. Where you are plausibly under-qualified on paper, the letter is the only place to make the argument for why the gap is smaller than it looks.
There is no posting. A speculative approach is a cover letter with a resume attached. Everything depends on the letter having a reason to exist.
Someone referred you. Name them in the first line. A referral converts far better than a cold application, and the letter is where the connection gets made explicit — see networking.

Spending the hours where they pay

A carefully researched letter takes forty minutes. Twenty applications a week with a letter each is thirteen hours, and if fifteen of those letters are attached to structured graduate forms nobody opens, most of that time bought nothing.

The better allocation is blunt: no letter where the route says it will not be read, a strong letter where it will, and the reclaimed hours spent on the two things that raise conversion everywhere — better evidence on the resume, and preparation for the stage that actually decides. For graduate schemes that means the written form answers and the assessment centre; for direct applications it means the interview.

This is not an argument for caring less. It is an argument for caring in the places where care is observable, which is a different thing and a considerably more effective one.

There is one exception to all of the above worth stating plainly: when an application explicitly asks for a letter and specifies what it should address, write it and address exactly that. A prompt like "tell us why this role and what you would bring in your first six months" is not a formality — it is a written question that will be read and, in a structured process, scored. Treat it as you would a form answer rather than as a covering note.

The same applies to a letter requested by a named person after a conversation. At that point it is not screening material at all; it is a document someone intends to forward internally on your behalf. Make it easy to forward — short, specific, and containing the one sentence they would want to quote when they pass it on.

Frequently asked questions

Should I write a cover letter if it says optional?

"Optional" usually means one person will glance at it and most will not. Write one if you have something the resume cannot say — a reason for approaching this employer, an explanation for something on the page, or a story that changes how a bullet reads. If you would only be restating the resume in prose, skip it and use the time on the resume itself.

Do graduate schemes read cover letters?

Large structured schemes generally screen on the application form, the online tests and the video interview rather than on an attached letter. The written questions on the form are the real thing to prepare — they are read, scored against a framework, and often weighted more heavily than anything else at that stage. Treat those answers with the care you would have given the letter.

What about a career change or an employment gap?

This is exactly where a letter earns its place. A resume can only show the gap; a letter can explain it in one unapologetic sentence and move on. The same is true of a career change, where the letter connects what you did to what you are applying for — a connection the reader will otherwise have to construct themselves, and usually will not.