To stop an AI-written cover letter sounding like everyone else's, you need to give the tool things only you have: real experiences, a specific reason for applying, your own way of putting things. Recruiters don't penalise AI. They penalise a letter that could have been sent by anyone.
Why do AI-written cover letters all sound the same?
Generative AI (ChatGPT, Gemini, Claude, Le Chat and the like) writes by choosing the most likely wording. Give it nothing but the job advert and your CV, and it produces an "average" letter: perfectly correct, but built from the same phrases it would use for any other candidate.
And more and more candidates are doing exactly that, while recruiters are dealing with a volume of applications that has grown sharply. According to the recruiting platform Ashby, applications per hire have tripled since 2021 and now exceed 300 on average, based mainly on US data. Across Europe, the Middle East and Africa, the figure has doubled over the same period.
The result: a recruiter can read the same line about "a company renowned for innovation" or "a profile combining rigour and drive" several times in a single afternoon.
How do recruiters spot a cover letter written with AI?
Rarely through the AI itself. As early as 2023, a US survey found that 82% of hiring managers couldn't tell a cover letter written by ChatGPT from one written by a person.
What they do spot is sameness: the same stock phrases, the same vague compliments about the company, the same lists of qualities with nothing to back them up. Researchers at Tilburg University have shown that the more candidates rely on the same tools, the less useful cover letters become for telling applicants apart. Recruiters then fall back on what AI can't invent: your genuine motivation and the link between your experience and the role.
What should you prepare before asking AI to write your cover letter?
AI can only personalise a letter with what you give it. That raw material needs preparing before you open the tool.
Start by rereading the job advert and noting what makes it specific: a project it mentions, the context (a newly created role, a team that's growing), a tool it names. That's often where your opening line is hiding.
Next, list two or three real experiences: a placement, a university or volunteer project, a problem you solved in a previous job. Note what you did and what came of it, with a figure if you have one.
Finally, write down in your own words why this employer rather than another: a product you use, an article you read, someone in your network who told you about them.
If you can't come up with a concrete reason, AI won't be able to invent a convincing one for you.
How do you write a prompt that gets you a personal cover letter?
The prompt (the instruction you give the AI) shapes the quality of what comes back. "Write me a cover letter for this job" gets you an average letter. A prompt built from your raw material gets you a draft worth working with.
Set out the context (role, employer, type of organisation), your experiences as you noted them, then your constraints: length, tone, phrases to avoid. For example: "Write a cover letter of no more than 250 words for the [job title] role at [company], an SME that [context from the advert]. Draw only on these two experiences: [experience 1 and result], [experience 2 and result]. My reason for applying: [reason]. Direct, understated tone. Don't use 'I am writing to apply', 'hard-working team player' or 'I believe I would be a great fit'."
Two tweaks improve the result further: ask the AI to put questions to you before it starts writing, or ask for two versions with different openings. And remember to strip your personal details (name, address, phone number) from anything you paste into the tool.
Which phrases should you spot and rewrite after generating your letter?
Even with a good prompt, the letter will often keep some tell-tale AI habits. Rewriting them is what makes it genuinely yours.
Stock openings and sign-offs
"I am thrilled to submit my application for…" and "I look forward to hearing from you at your earliest convenience" tell the reader nothing. Open instead with your reason for applying, and close by naming the part of your background you'd like to talk through at interview.
Strings of adjectives
"Motivated, detail-oriented and proactive": cut it. If one of your examples already demonstrates the quality, the adjective adds nothing. If none does, it won't convince anyone.
Generic compliments about the employer
"Your company, renowned for its commitment to excellence" could describe thousands of businesses. Replace it with the specific detail you picked out while preparing.
An overly even rhythm
Sentences of identical length, all built the same way, are a giveaway of generated text. Read the letter aloud and rephrase it in the words you'd actually use when speaking.
How can you check that no other candidate could have signed your cover letter?
Start with the swap test: mentally replace the employer's name with a competitor's, and your name with another candidate's. If the letter still works, it isn't personal enough yet.
Then run the interview test: for every sentence, ask yourself whether you could talk about it for a full minute. An "ability to bring teams together" that you can't illustrate with a single real situation will catch you out.
Finally, check the facts. AI can embellish an experience or add something inaccurate about the employer. Check every fact, figure and name before you hit send.
Key takeaways
- Recruiters reject an interchangeable letter, not a letter written with AI.
- Personalisation starts before you open the tool: real experiences, a specific detail from the advert, a genuine reason for applying.
- A precise prompt, with your experiences and the phrases to avoid, gives you a far more usable draft.
- Stock openings, strings of adjectives and generic compliments are the first things to rewrite.
- The swap test tells you in a minute whether the letter is really yours.
- Check every fact before sending: AI can get things wrong or embellish.
FAQ: your questions about writing a cover letter with AI
Should you tell the employer you used AI? There's no obligation to. What matters is that the content is accurate and that you can stand behind it at interview. If you're asked, simply explain how you used the tool.
Can AI detectors get my cover letter rejected? Some recruiters do use them, but their reliability is still debated, especially on short texts. A letter built around specific facts and rewritten in your own words is less exposed to that risk.
Can you use AI for a graduate scheme or apprenticeship cover letter? Yes, with the same method. Your real experiences will come from placements, university projects or volunteering.
Which AI tool is best for writing a cover letter? The main tools produce similar results for this kind of text. The quality depends far more on the information you provide and on your rewriting.
Do you need to rewrite the AI's cover letter from scratch? Not necessarily. The structure can stay, but the opening, the examples and the closing should carry your voice: they're the parts recruiters read most closely.
