What are the mistakes that get a cover letter skipped?

A cover letter gets skipped for restating the resume, going out unchanged to every company, opening "To Whom It May Concern", making claims with no outcome attached, and — the one that ends it outright — naming the wrong company. Each is a rewrite rather than a rethink. Do not include salary history, and do not proofread only once.

• A letter that summarises the resume spends its one page on information the reader already has.
• One sentence that could only have been written about this company is what separates a customised letter from a template with the name swapped.
• Every claim needs an outcome attached to it. "Results-driven" is not evidence of anything.
• Salary history, reasons for leaving, and anything negative about a former employer stay out.
• The letter is framed around what you will deliver, not what the role will do for you.
• Company name, role title and recipient name get checked in a separate pass, after the content pass.

Which mistakes disqualify you outright?​

The proper nouns. A letter addressed to the wrong company — almost always because it was adapted from the last one — makes the decision for the reader in a second. The same goes for a role title that does not exist there, a misspelled recipient name, and the wrong file attached. None of these are judgements about your experience; they are one mechanical failure, and they all come from editing a previous letter under time pressure.

Typos sit just behind them, clustering in predictable places: their/there/they're, your/you're, tenses that drift when you have rewritten a sentence twice, and run-ons in the paragraph you wrote last.

The fix is procedural rather than clever: proper nouns get their own pass, last, after you have stopped changing sentences. If the structure itself is what needs work, start with the six parts of a cover letter.

What does "customised" actually require?​

One or two sentences that could not appear in a letter to any other company. That is the whole bar, and it is lower than it sounds — ten to fifteen minutes on the About page, recent news, and whatever they are currently shipping will produce them.

Instead of "I'm excited about this opportunity at your company", a line like "[Company]'s commitment to sustainable technology lines up with my experience leading green initiatives that reduced carbon footprint by 34%" ties one of your outcomes to something they said about themselves.

The related failure is writing about yourself without connecting anything to the posting. Every paragraph should answer a requirement, in their words where their words are reasonable. Instead of "I have extensive experience in marketing", a line like "Your posting emphasises scaling marketing operations — I grew a marketing team from 2 to 12 people while raising campaign throughput 45%" reads as a response rather than an introduction.

How do you back a claim without boasting?​

Replace the adjective with the outcome. The claim is not the problem; the missing evidence is.

Instead of "I'm a results-driven professional with strong leadership skills", a line like "I delivered a product launch two weeks ahead of schedule, worth $1.2M in first-quarter revenue" says the same thing and can be discussed. Instead of "I'm a great communicator", name the audience and the result.

One constraint on this: only use numbers you can defend out loud. A figure in a letter is an invitation to ask about it in the first interview, and a number you cannot reconstruct is worse than no number. If the only version you have is approximate, say so in the letter — "roughly a third of the pipeline" survives a follow-up question better than a precise figure you invented.

What should never appear in a cover letter?​

Salary history and salary expectations, unless the application explicitly asks. A reason for leaving your current role, unless it is genuinely neutral. Anything negative about a former employer, manager or colleague — the reader has no way to verify your side and will price in the risk. Personal circumstances, family details, unrelated hobbies, and a full chronological account of your career, which is what the resume is for.

The subtler version is a letter about what you want. "This role would help me grow my product management skills" tells the reader what the job does for you, when what they are deciding is what you do for them. A line like "My experience scaling products from concept to $10M in revenue positions me to accelerate your roadmap" is the same enthusiasm pointed the other way.

Is a generic letter worse than sending none?​

Yes, where the application does not ask for one. A letter that reads as mass-produced adds a data point about your judgement and nothing about your fit, so the reader spends time to learn nothing.

The condition that flips it is the form: send a letter whenever the application gives you a field for it, and skip it when there is no upload field or the posting says resume only. That is a recommendation rather than a rule, and it holds because a field for a letter usually means someone intends to read it. When you do send one, write it for that company — customising is what makes a letter worth the reader's time, not its existence.

If silence is the problem you are actually trying to solve, the letter is rarely the largest cause. Rule the others out first: why you might not be getting interview callbacks.

What is worth checking last, and what will not be checked for you?​

Read the letter aloud once, for flow and for anything that sounds unlike you. Then run the mechanical pass: company name, role title exactly as the posting writes it, recipient name spelling, every number, and the file you are about to attach.

FluxResume keeps letters on the Cover Letters tab of the Documents hub, and that tab appears only when Cover Letter is on for your plan. The Cover Letter editor has a Smart Mode panel with job, resume, recipient and tone; Regenerate rewrites from those settings, Humanize softens AI tone once a draft exists, and word and sentence counts sit under the page. The recipient field searches people saved in Contacts, which is where the correct spelling of a name is already stored.

What the product will not do is catch any of the mistakes above. There is no proofreading reminder, no grammar or spell check, and nothing comparing the company name in your letter against the company on the job. Regenerate will rewrite a letter naming the wrong employer and hand it back with the wrong employer still in it. That pass is yours, and it is the one worth protecting when you are applying quickly. Finished examples: https://fluxresume.io/cover-letter-examples/.

Common questions​

How much research does one letter need?​

Ten to fifteen minutes. Read the About or mission page, scan the last two or three pieces of company news, and look at what they are currently building or selling. You are looking for one specific thing you can tie to one of your own outcomes. More research does not improve the letter much past that, because there is only room for one or two company-specific sentences before it stops being about you.

Should you explain an employment gap in the letter?​

One sentence, factual and forward-looking, and only if the gap is visible on the resume and long enough to be the reader's first question. Name the period, name anything relevant you kept current, then move to what you are ready to do now. Do not apologise and do not over-explain — a paragraph on a gap reads as more of a problem than a line does. A prompt scaffold for the phrasing sits in the AI drafting guide, and what the resume itself should do with the dates is how to explain a gap in your employment history.

How do you proofread your own writing?​

Change how you read it. Read aloud, read it on your phone instead of your laptop, or read the paragraphs bottom to top so the structure stops carrying you past errors. Then run a separate pass that looks only at proper nouns and numbers, ignoring the prose. Grammar tools catch mechanical errors and will not flag a correctly spelled wrong company name, which is the error that matters most.

Can one letter be reused across similar roles?​

The structure and the achievement paragraphs can be; the hook, the company-specific sentence and the requirement mapping cannot. In practice the middle of the letter is stable and the first and last paragraphs get rewritten each time. This is also where wrong-company errors come from, so delete the old company's name from every paragraph before you start typing the new one rather than editing over it.

Originally published February 2025. Reviewed and rewritten for FluxResume in August 2026.