How to write a cover letter

What a cover letter should and should not do

A cover letter is not a prose version of your resume. Hiring managers already have your resume. The letter should answer three questions the resume cannot: Why this company? Why this role? Why now in your career? If your letter could be sent to any employer, it is not doing its job.

Keep it to three or four short paragraphs and under 400 words. In the US, Canada, the UK and Australia, one page is the universal expectation. Anything longer signals poor editing, which is itself a red flag for roles that require written communication.

The four-part structure that works

Every effective cover letter follows the same skeleton. Once you have this skeleton, tailoring becomes a matter of swapping specific details rather than rewriting from scratch.

1. Opening line: name the role and give one concrete reason you want it at this company specifically.
2. Proof paragraph: pick two or three achievements from your resume that directly match the job's top requirements. Add a number to each one if you can.
3. Connection paragraph: show you understand what the company is trying to do and explain how your background helps them do it.
4. Closing line: state you would welcome a conversation, thank them for their time, and stop. Do not beg or over-explain.

Example sentences for each part

Seeing the structure in action makes it easier to write your own version. The examples below are for a marketing manager role at a mid-size SaaS company, but the pattern transfers to any field.

• Opening: 'I am applying for the Marketing Manager role at Acme because your recent shift toward product-led growth is exactly the motion I have spent the last three years building at two B2B startups.'
• Proof: 'At Riverline, I led a content programme that grew organic pipeline from 12% to 31% of total revenue over 18 months. At my previous company I managed a team of four and cut cost-per-lead by 22% through channel consolidation.'
• Connection: 'Your job posting mentions expanding into the mid-market segment. I have run two mid-market launches and know the messaging and sales-enablement work that segment requires.'
• Closing: 'I would welcome the chance to talk through how my experience maps to your goals. Thank you for your time.'

How to tailor without starting from scratch

The mistake most people make is treating every cover letter as a blank page. Instead, build one master letter for each type of role you are applying for, then make three targeted edits per application.

Read the job posting carefully and identify the top two or three requirements. Check which of your achievements speaks most directly to each one. Then update the opening line with the company name and a specific detail you found on their website or in the posting, swap in the most relevant achievements in the proof paragraph, and adjust the connection paragraph to reflect what that particular company is working on.

Those three edits take 10 to 15 minutes and produce a letter that reads as genuinely tailored, because it is.

Formatting and submission details

Use the same font and header as your resume so the two documents look like a set. Standard choices are Calibri, Georgia or Arial at 10 to 12 points with margins of at least 0.75 inches.

Address the letter to a named person wherever possible. Check LinkedIn or the company website for the hiring manager's name. If you cannot find one, 'Dear Hiring Team' is acceptable. Avoid 'To Whom It May Concern', which reads as low effort.

Save the file as a PDF unless the application system specifies otherwise. Name the file clearly: FirstnameLastname-CoverLetter-CompanyName.pdf. Some applicant tracking systems in the US and Canada parse file names, and a clear name helps if a recruiter is searching their inbox later.

Common mistakes that get cover letters ignored

Even a well-structured letter can be dismissed for avoidable reasons. Watch for these.

• Opening with 'I am writing to apply for': it wastes the first line, which is the most-read part of the letter.
• Repeating resume bullet points word for word: the letter should add context, not duplicate content.
• Vague claims without evidence: 'I am a strong communicator' means nothing without an example.
• Mentioning salary expectations unless the posting specifically asks for them.
• Spelling the company name wrong or leaving in a previous employer's name from a copy-paste.

Using Break-In Bad to write and submit tailored cover letters

If you are applying to multiple roles, Break-In Bad can handle the tailoring work for you. Once you have confirmed your background through a conversation with Omar, she writes a tailored resume and cover letter for each job using only facts you have verified. Nothing is invented. You review the output before anything is submitted.

Omar then applies on your behalf through Greenhouse, Lever, Workday and other employer sites, and sends you a screenshot as proof of each submission. Credits start at 25 for $9 and never expire, so you can apply at your own pace without a subscription.