Are cover letters necessary?
Sometimes. A cover letter is necessary when the posting or the application form asks for one, and then a missing letter can sink the application. When it is optional, a short letter helps only if it adds evidence your resume can't show. When there is no field for one, skip it.
The answer depends on the employer, and the employer tells you. Read the "how to apply" or "required documents" part of the posting before you write anything. If the form has a required upload marked "cover letter," the decision is made. If the form has an optional box, the rest of this page will help you decide.
Few employers publish whether they read optional letters, so be careful with any blanket rule. Some public employers do publish their own guidance, and it is worth reading what they say.
What do employers' own hiring guides say?
The few public guides that address it treat the letter as optional but useful. The Ontario Public Service guide says a cover letter "is not mandatory" in the OPS. It still calls the letter "the ideal tool to display how you meet the qualifications" of a job. Canada's federal public service often uses screening questions instead.
The Ontario guide, Writing a cover letter and résumé: tips, tools and resources, is dated October 2015, so check current postings for changes. It says your application "will be carefully screened and evaluated against the qualifications outlined in the job advertisement." It sets a five page limit for the cover letter and resume combined, and suggests a letter of one to two pages.
The same guide is frank about what its screeners ignore. Some employers want to know how you heard about the job and why you are interested. In the OPS, it says, "this information is not used as part of the screening criteria." The useful part of the letter is the part that matches you to the qualifications.
When does a cover letter get replaced by screening questions?
Many Government of Canada postings ask screening questions tied to the job's qualifications. Your answers do the work a cover letter would do elsewhere. Treat each answer as a short letter about one requirement. Give a specific example for each one, using the posting's own words.
The Public Service Commission page on applying for Government of Canada jobs, modified September 28, 2026, explains the rules. It says "you may need to answer screening questions related to the qualifications on the job poster." It also says, "Don't just state that you have the experience or education; provide details or examples."
Its keyword advice is unusually direct: "Use the exact keywords and skills from the screening question in your answer. Do not use synonyms." If a question uses "and," you must show every skill it lists. If it uses "or," one is enough. That is good advice for any cover letter that answers a list of requirements.
Does AI make cover letters less useful?
Possibly, on some platforms. A 2025 working paper by Anais Galdin and Jesse Silbert studied applications on Freelancer.com. It found that employers there valued applications tailored to the job before large language models spread, and stopped valuing them after. That is one platform, so treat it as a warning sign rather than a rule.
The paper, Making Talk Cheap: Generative AI and Labor Market Signaling, was posted to arXiv on November 11, 2025. Its argument is that writing used to be costly, so a tailored letter signalled effort. Once a model can write that letter in seconds, tailored writing tells the employer less.
The practical lesson is about what goes in the letter. Polished phrasing is now cheap for everyone. Specific facts from your own work are still hard to copy. A letter that names a project, a number and a result tied to the posting carries more information than a letter that only sounds good.
When should you send one, and when can you skip it?
Send one whenever it is required, and when you have something to explain that your resume can't. Career changes, gaps, relocation and a referral name all belong in a letter. Skip it when there is no field for it. When it is optional and you have nothing to add, a few honest lines are enough.
Use this table as a starting point. It is advice, and the posting always wins.
| Situation | Send a cover letter? | What it should do |
|---|---|---|
| The posting or form says a cover letter is required | Yes | Answer each key requirement with evidence |
| The posting asks you to answer a question in the letter | Yes | Answer that question first and plainly |
| Optional field, and you are changing careers | Yes | Link your old work to the new job's requirements |
| Optional field, and you have a gap or are relocating | Yes | Explain it in two or three sentences |
| Optional field, and someone referred you | Yes | Name the person and how you know them |
| Optional field, strong match, nothing to explain | Your call | Keep it short and specific, or skip it |
| Screening questions instead of a letter | No letter | Answer each question with a specific example |
| No field and no instruction | No | Put the effort into the resume |
If you send one, make it specific. Monroe Community College's career center advises that a letter should not exceed one page and warns against sending the same exact letter to multiple employers. The University of Northern British Columbia's cover letter handout says the same: "Don't send a generic cover letter to many different companies."
What does a short optional cover letter look like?
It can be four or five sentences. Name the job, give one or two facts that match the top requirements, and explain anything the resume leaves open. Then stop. A short letter with real evidence respects the reader's time and still answers the question the reader has about you.
Here is a made-up example for an optional field. Change every detail to your own facts.
Dear hiring team, I'm applying for the Operations Coordinator role (job ID 4471). Your posting asks for experience scheduling field crews; at Lakeside Utilities I scheduled 14 crews across three towns for two years. I moved to Calgary in August, so I can start in person right away. My resume has the details, and I'd welcome a conversation. Thank you, [your name]
That example does three jobs. It names the role, proves the top requirement with a fact, and explains the move. Every claim in it should come from your resume or your own records.
How do you write one quickly without making things up?
Start from the posting and your resume, not from a template. Pick the two or three requirements that matter most, and find the line on your resume that proves each one. Write one paragraph per requirement from that evidence, then add a short opening and closing.
Our guide on how to write a cover letter walks through each paragraph with examples. The free cover letter generator does the matching for you: upload your resume, paste the job, and every claim in the letter comes from your resume. Each paragraph answers one requirement and shows the lines it rests on.
Your resume still carries most of the weight, so tailor it first. The guide to tailoring a resume without lying covers how to match the posting with true facts. The free resume optimizer rewrites the lines that matter for the job and keeps your facts. If you are changing fields, read the career change resume guide before you write the letter.
How much time should a cover letter take?
Spend time in proportion to how much you want the job. For a role you have a referral for, or one you would move for, a careful letter is worth an hour. For an optional field on a long shot, a few true sentences are enough. Most of your effort belongs in tailoring the resume.
The page on tailored applications vs mass applying explains why fewer, better applications tend to pay off. If someone inside the company can refer you, the guide to getting a referral shows how to ask. A referral name in the first line of a letter is one of the clearest reasons to write one.
If you have a gap to explain, keep the letter's explanation short and match it to the resume. Our page on explaining a resume gap has wording you can adapt for both.