What optional actually signals
When a job posting or application portal marks the cover letter field as optional, it usually means the applicant tracking system does not require it to submit, not that the hiring manager does not care whether one exists. Some companies mark it optional simply because their system defaults that way, while the actual reviewer still reads every letter submitted. Others genuinely do not weigh it much. You generally cannot tell which situation you are in from the posting alone, so the safer assumption is that submitting a good one can only help.
When sending one is clearly worth it
A cover letter is worth writing, even when optional, in a few common situations:
- You are changing industries or job functions and your resume alone does not explain the connection.
- You have an employment gap or an unusual pattern in your work history that benefits from brief context.
- You are applying through a referral and want to name that connection explicitly.
- The role is competitive and you want any edge available.
- You have a genuinely specific reason for wanting this company, not a generic one.
When skipping it is genuinely fine
If your resume is a clean, direct match for the role, your background needs no extra explanation, and the application process is clearly high volume with a fast turnaround, skipping an optional cover letter rarely costs you much. In these cases, a generic, rushed letter that adds nothing can do more harm than good, since it signals low effort more than a missing letter would. The rule of thumb: only send one if you can write something that adds real information, not just restates your resume.
A weak cover letter can hurt more than no cover letter
A generic, templated cover letter that clearly was not customized for the role is often worse than sending none at all, because it actively demonstrates low effort in a case where nothing was required of you. If you are going to submit one, it needs to meet the same bar as a required cover letter, specific, tailored, and worth the reader's time. Do not submit a filler letter just to check a box.
A quick way to decide
Ask yourself one question: does my resume alone tell the full story of why I am a strong fit for this exact role. If yes, an optional letter can be skipped without concern. If no, because of a career change, a gap, a referral, or a specific reason for wanting this company, write a short, focused letter and submit it even though it was not required.
How much time is reasonable to invest in an optional letter
Since the letter is not required, it makes sense to calibrate your time investment to the value of the role. For a role you are genuinely excited about, or one where you have a real edge to communicate, spending real effort on a focused, well edited letter is worthwhile. For a role you are applying to more speculatively, among many similar applications, it may be more efficient to skip the optional letter entirely and put that time toward tailoring your resume instead, which every application requires regardless. Think of your limited time as a budget and spend it where a cover letter can move the needle most.
What many recruiters actually do with optional letters
In practice, many recruiters skim an optional cover letter only if the resume already looks promising, using the letter as a tiebreaker or a way to build a stronger case internally when advocating for a candidate to the hiring manager. This means a strong optional letter can genuinely help move a borderline resume forward, while a weak one attached to a strong resume rarely does much damage, since the resume was already going to be considered on its own merits. The asymmetry favors writing a good one when you have time, and skipping it cleanly when you do not.
Norms vary noticeably by industry and role level
In fields like design, writing, marketing, and other roles where communication and persuasion are part of the job itself, an optional cover letter is more likely to be read closely, since the letter doubles as a small work sample. In highly technical or high volume operational roles, an optional letter is more likely to be skipped by both the candidate and the reader. Senior and leadership roles tend to sit in between, where a thoughtful letter can help establish strategic thinking and communication style even though the interview process will ultimately carry more weight than the letter itself. When in doubt, look at how the company's other materials read. A careful, well written job posting often comes from a team that will actually read a careful, well written letter.
One more consideration before you decide
If you are genuinely unsure whether writing an optional letter is worth your time for a given role, a reasonable default is to spend fifteen minutes drafting a short, three paragraph version focused only on your strongest, most relevant point. If it comes together quickly and reads well, submit it. If it feels forced or you cannot find anything specific to say, that itself is useful information, and skipping it is the right call for that particular application.
Trust your own judgment over a fixed rule
No single rule about optional cover letters applies perfectly to every situation, since roles, companies, and your own circumstances all vary. Use the guidance here as a starting framework, then adjust based on what you know about the specific role and how much you have to gain from standing out in that particular pool of applicants.
Over time, most job seekers develop a reasonably good instinct for which applications deserve the extra effort. Trust that instinct once you have applied the basic framework a few times, and let it guide faster decisions later in a long search.