Most cover letter mistakes are easy to catch and costly to miss: the wrong company name, a letter that could go to any employer, no evidence, or a greeting and sign-off that don't match. Run these ten checks on every letter before you send it. Each one comes from a careers service, listed under Sources.
1. The company and contact details are right
Reusing a letter is how the last company's name ends up in this one. The UK National Careers Service lists checking the company name and the recruiter's details as a step of its own. Search the letter for every company name in it.
2. The opening names the role
Say which job you are applying for, and where you saw it, in the first paragraph. The National Careers Service adds the reference number if there is one; Prospects suggests saying when you can start.
3. It greets a person where possible
The National Careers Service, Prospects and Harvard's career office all say to address the letter to someone by name if you can. Prospects suggests checking the company site or calling to ask. Use a general greeting only when you cannot find a name.
4. The sign-off matches the greeting (UK)
In British letters, "Yours sincerely" follows a named greeting and "Yours faithfully" follows "Dear Sir or Madam". The National Careers Service and Prospects both give this rule.
5. It uses the job post's words
The National Careers Service says to use the keywords from the employer's advert. Harvard says to reference skills or experiences from the job description and draw the connection to your own. Use them where they are true, in sentences, not as a list.
6. There is at least one specific example
Harvard asks for examples that support your skills. "I am a hard-working team player" proves nothing. "I rebuilt the weekly sales report so it refreshes itself every Monday" gives the reader something to ask about in the interview. A number helps when you have a real one.
7. It doesn't repeat your resume
Prospects lists repeating the CV as a common mistake: the two documents should complement each other. Pick two or three results that match this job and leave the rest to the resume.
8. It was written for this job
Prospects and the National Careers Service both say to write a new letter for every application, and Prospects says templates should only be a guide. Check for leftover placeholders such as [Company] or [Your reason here]. Harvard's guidance on AI adds that generated drafts tend to be generic; read it aloud and ask whether it sounds like you and makes a case with accurate examples.
9. It fits on one page
The National Careers Service describes three to five paragraphs; Prospects and Harvard set one page as the limit. If it runs over, cut the paragraph that repeats the resume.
10. It is proofread, and matches the resume
Check spelling and grammar before you send; Prospects suggests leaving it for a while first, because mistakes are hard to spot straight after writing. Harvard and the National Careers Service also say to use the same font and size as your resume, and to check that your contact details are the same on both. If you send a PDF, open it and check the formatting survived.
Run most of these in one go
The cover letter checker runs most of these: it looks for the company and the role, a greeting to a named person, the job post's key words, a result with a number, stock phrases, template gaps left in, paragraph count and length. It cannot tell whether a name is the right one, and it does not check spelling or grammar, so do checks 1 and 10 yourself. Your letter stays in your browser tab.
If the fixes add up to a rewrite, start a new draft from your resume. For the resume side of the same problem, see common resume mistakes and how to tailor your resume to a job description.
Questions people ask
- What is the most common cover letter mistake?
- Sending one generic letter to every employer. It is also how the wrong company name ends up in a letter. Write a new letter for each job and check every name before you send.
- Is it okay to use a cover letter template?
- As a guide to structure, yes. Prospects says templates should only be used as a guide. Replace every line with your own facts and remove any leftover placeholders.
- Can I use AI to write my cover letter?
- You can use it for a first draft or feedback, but edit it until every example is accurate and it sounds like you. Harvard's career office notes AI output is likely to be generic, and some employers have rules about AI in applications.
- Does the free cover letter checker fix grammar?
- No. It checks structure and content: company and role, greeting, key words from the job post, results, stock phrases, template gaps and length. Use a grammar checker for spelling and grammar.