How to write a cover letter
By Dexaloop · Updated 27 October 2026 · Checked against the sources listed below
A good cover letter fits on one page, runs three or four short paragraphs, is addressed to a named person where possible, and is written fresh for each job. The opening says which role you want and how you found it, the middle connects two or three of your strongest points to what the employer needs, and the close thanks them and asks for the next step. It should add to your resume, not repeat it.
What a cover letter is for
Your resume lists what you have done. The cover letter explains why you want this particular job and why your background fits it. It is also the first sample of your writing the employer sees, so clarity counts as much as content. MIT's career office stresses that "Careful composing and revision are essential."
Length and layout
The career services we checked agree on one page. MIT says "A cover letter should be no longer than one page with a font size between 10-12 points." Monroe Community College's career center is tighter: "Limit your cover letter to 3 to 4 brief paragraphs, with a total length of one-half to three-quarters of a page." The UK National Careers Service describes it as "a short letter, usually 3 to 5 paragraphs long."
Use the same font as your resume so the two look like a set, keep margins of at least half an inch (Monroe's advice), and put your contact details at the top.
The structure, paragraph by paragraph
| Part | What it does | What to include |
|---|---|---|
| Greeting | Shows you did your homework | A named person if you can find one; otherwise "Dear Hiring Manager" |
| Opening paragraph | States the purpose | The exact job title, where you saw it, and one line on who you are |
| Middle paragraph(s) | Makes the case | Two or three skills or results, each tied to something in the job ad |
| Closing paragraph | Asks for the next step | Restate your interest, thank them, say how to reach you |
| Sign-off | Ends formally | "Sincerely" in the US; in the UK "Yours sincerely" with a name, "Yours faithfully" after "Dear Sir or Madam" |
For the opening, MIT says to "State clearly in your opening sentence the purpose for your letter and a brief professional introduction." The National Careers Service adds: "Introduce yourself and explain how you found the advertised job." For the middle, MIT's advice is to "Discuss what skills you have developed and connect these back to the target role." For the close, "Restate succinctly your interest in the role and why you are a good candidate," and the UK service suggests you "Thank the employer for considering your application."
Tailoring: the part most people skip
Every source we checked says the same thing. MIT: "Be sure that each cover letter is specifically tailored to the company you are writing to." The National Careers Service: "write a new one for every job you apply for and make sure it's tailored to the company and the specific role." Monroe lists "Original (avoid mailing the same exact letter to multiple employers)."
Tailoring does not mean starting from zero each time. Keep a file of strong sentences about your achievements, then pick and adapt the ones that match each posting. Name the company, mention something specific about it from its website, and use the job ad's words for the skills it asks for.
Worked example: planning a one-page letter
Jordan is applying for a "Customer Success Associate" role. The ad asks for three things: experience handling customer questions, comfort with a help desk tool, and clear written communication. Jordan plans the letter before writing:
- Opening (2 sentences): the job title, that the ad was on the company's careers page, and that Jordan has 2 years in retail customer service.
- Middle paragraph 1 (3 sentences): handled about 40 customer queries a day at the store's service desk, and logged each one in the store's ticket system. That covers the first two requirements.
- Middle paragraph 2 (3 sentences): wrote the store's returns guide used by 12 new staff. That covers written communication.
- Close (2 sentences): interest in the company's product, thanks, phone and email.
That is 10 sentences. At roughly 20 to 25 words a sentence, the body comes to about 200 to 250 words, which leaves room for the address block and sign-off on one page. Each of the 3 requirements in the ad is answered once, with a number behind it, and nothing is copied from the resume word for word.
Common mistakes
- Repeating the resume. MIT says "Try not to simply repeat your resume in paragraph form," and Houston's Bauer career center puts it as "your cover letter shouldn't rehash your resume."
- Going too long. Bauer notes employers "often don't have time to read a two-page letter" and suggests "highlighting 2-3 key things."
- Starting every sentence with "I". Monroe lists this as a mistake. Vary the openings: "At my last job...", "In two years at the desk...".
- Slang, jargon or exaggeration. Monroe again: "Keep the language professional."
- Typos and the wrong company name. A letter that names a different employer, often left over from the last application, is an instant giveaway that it was not tailored. Have someone else proofread it.
- Forgetting the job reference. If the ad lists a job code, Monroe says to reference it.
Sending it
Follow the posting's instructions: paste into a form, attach as a separate file, or combine with your resume. If you attach it, save a PDF so the layout does not shift, and name the file clearly, for example "Jordan-Lee-Cover-Letter.pdf."
Writing it in Dossier
Dossier, our free resume maker for iPhone and iPad, includes a cover letter maker. Writing the letter is free; exporting a letter as a PDF is part of Dossier's optional one-time Premium. Resume PDF export is free with no watermark, and everything stays on your device.
Write your cover letter in Dossier: dexaloop.com/dossier/. Free, no sign-up, and it runs on your device.
Questions
How long should a cover letter be?
No more than one page. MIT's career office says a cover letter should be no longer than one page, and Monroe Community College suggests 3 to 4 brief paragraphs filling one-half to three-quarters of a page.
Who do I address it to if I can't find a name?
Try the job ad, the company website or a phone call first. If you still have no name, MIT suggests Dear Hiring Manager. In the UK, a letter that opens Dear Sir or Madam ends Yours faithfully.
Do I still need a cover letter if the application says optional?
It is your one chance to explain why you want this job and connect your experience to it in your own words, so a short, tailored letter is usually worth writing. A generic one adds little.
Can I reuse the same cover letter?
Reuse your best sentences, not the letter. The National Careers Service says to write a new one for every job you apply for and tailor it to the company and the specific role.
Should the cover letter repeat my resume?
No. MIT advises against simply repeating your resume in paragraph form. Pick two or three points and show how they fit this job.
Yours sincerely or Yours faithfully?
In UK usage, end with Yours sincerely when you used the person's name and Yours faithfully when you wrote Dear Sir or Madam. In the US, Sincerely works for both.
Sources
- MIT CAPD: How to write an effective cover letter
- National Careers Service (UK): How to write a cover letter
- Monroe Community College Career Center: Writing a cover letter
- University of Houston Bauer College, Rockwell Career Center: Top 3 cover letter mistakes
This guide is general information, not legal, tax or financial advice. Rules change; check the official source for your own case. Found a mistake? Email support@dexaloop.com.