A letter of interest is a short message you send to an employer that has not advertised the job you want, telling them who you are and what you could take off their plate. Because there is no posting to respond to, you cannot mirror a job description back at them, so you have to propose the role yourself and justify why it should exist. Keep it to one page, aim it at a named person on the team you want to join, and open with a specific problem you could solve for them rather than a summary of your career.
The definition
What a letter of interest is
A letter of interest is an unsolicited note to an employer you want to work for, sent when they have not advertised the role you are after. You will also see it called a letter of inquiry, an expression of interest, or a prospecting letter. They all describe the same move: you go first, before a requisition exists, and you make the case that hiring you would be worth the trouble of opening one. It is lowercase in a sentence, by the way. Only capitalize it if it is sitting in a heading or a subject line.
The moment to send one is when you have a reason that is specific to them and not to you. A team just shipped something and is obviously stretched thin. A company raised money and is expanding into a market you know cold. Somebody you met at a conference described a problem you have already solved twice. A role you want keeps getting posted, filled, and posted again, which tells you the demand is real even when the listing is down. In each of those cases you have something to say that a stranger could not say, which is the only thing that gets an unsolicited email read.
One scope note, because the phrase gets used in several unrelated places. This guide is about employment letters. Medical residency programs, medical schools, and college admissions offices also ask for letters of interest, and those follow rules the programs set themselves, including strict timing windows. Do not carry the advice below into those. Everything here is aimed at a company, a hiring manager, and a job that does not exist yet.
Side by side
Letter of interest vs cover letter vs letter of intent
Two of these are job-search documents and one is a business document that people confuse with the first two. The rows sort them out.
| Capability | Folio | Cover letter | Letter of intent |
|---|---|---|---|
| What starts it | Letter of interest: nothing is posted, and you reach out anyway | An open, advertised role you are formally applying to | A deal, an offer, or a partnership being outlined before contracts |
| Who reads it | Letter of interest: a manager who was not expecting to hear from anyone | A recruiter or manager already reviewing a stack of applicants | The other side of a negotiation, and often their lawyer |
| The core argument | Letter of interest: here is a problem you have, and here is why I could take it | Here is why my record matches the requirements you listed | Here are the terms both parties expect to agree to |
| The ask | Letter of interest: fifteen minutes, or a pointer to the right person | An interview for the specific job you applied to | Signatures, or a move to a binding contract |
| Legal weight | Letter of interest: none. It is a job-hunting note, not a commitment | None. It is part of an application | Sometimes real. Clauses can bind, which is why lawyers read them |
| Where it goes | Letter of interest: an email to a named person, or a talent-network form | Uploaded into an application portal next to your resume | Exchanged between the two parties to the deal |
The middle column is the letter of interest. If someone at work hands you a letter of intent, that is a different document entirely and you should read it slowly.
The anatomy
What should a letter of interest include
Six parts, in this order. Nothing else earns its space on a page that nobody asked you to send.
Subject
Name the team and the reason
The subject line is the whole gamble, because it decides whether paragraph one gets read. Skip "Job inquiry" and write the thing you actually want to talk about, such as "Onboarding drop-off on the growth team". Specific beats polite here.
Opening
Why them, in one sentence
Say what you noticed about their work and why it made you write. This is the sentence that proves you are not sending the same letter to forty companies, and it is the only defense you have against being read as a mass email.
Proof
One outcome, with a number on it
Pick the single result closest to the problem you just named and give it a figure, a timeframe, and a scope. One well-chosen outcome lands harder than a paragraph of adjectives about being passionate and detail-oriented.
Fit
The role you are proposing
Because nothing is posted, you have to describe the shape of the job you would do. Two lines is enough. It gives the manager something concrete to react to instead of leaving them to invent a role on your behalf.
Ask
One small, specific next step
Ask for a short call, or ask who else you should be talking to. A tiny ask is easy to say yes to. "Let me know if you have anything available" puts the work on the reader and usually gets nothing back.
Signature
A link worth clicking
Close with your name and one URL that shows the work, ideally your own site rather than a profile page you do not control. The letter makes the claim, the link is where they go to check it.
The method
How to write a letter of interest for a job
The writing is the last step, not the first. Do these five in order and the letter mostly writes itself.
Pick a team, not a company.
Companies do not hire, teams do. Decide which group you would join and who runs it, because a letter aimed at the whole organization has no obvious owner, and a letter with no owner is a letter nobody feels responsible for answering.
Find the problem worth solving.
Read what they shipped, what they wrote, what they keep hiring for, and what customers complain about in public. You are looking for one gap you could credibly close. Without it you have nothing to open with and no reason to be writing.
Find a name.
Ten minutes on the team page, the changelog bylines, and the conference talks will usually surface the manager. A named recipient turns an unsolicited email into a personal one, and personal email is the kind that gets an answer.
Draft it from your own record.
Pull the letter from the outcomes you have already written down rather than starting on a blank page. In Folio you enter the company and leave the role blank, and the letter opens on the opportunity at that company instead of a job title that does not exist.
Send it, log it, follow up once.
Paste it into an email, send it to one person, and record the date. A single follow-up after seven to ten days is fair. A second one is not. Folio tracks the ones you send alongside your normal applications so nothing quietly goes cold.
The recipient
Who to address a letter of interest to
Aim for the person who would be your manager. Not HR, not a recruiter, not a generic careers address. Recruiters work from open requisitions, and the entire premise of your letter is that no requisition is open, so a recruiter has no box to put you in and will file you accordingly. The manager is the only person who can look at your note and think that they should probably create a role. Their name is usually findable: the team page, the byline on the engineering or design blog, the speaker list from a meetup, the person quoted in the launch announcement.
If you genuinely cannot find a name, do not fall back on "To Whom It May Concern". It reads like a form letter from 1994 and it tells the reader that you did not look. "Dear Hiring Team," is honest, current, and does not pretend to a familiarity you have not earned. Folio does this for you: when no hiring manager is set, the recipient block and the greeting both fall back to the hiring team rather than leaving an awkward blank where a name should be.
One more rule. Send it to one person. Copying four people at the same company, or sending near-identical letters to several of them in the same week, is the fastest way to look like a mail merge. They talk to each other. Pick the best single recipient, write to them like a person, and if you get no reply after a follow-up, then it is fair to try a different team.
Inside the building
The letter of interest for an internal position
The internal version is a different letter, and most people get it wrong by writing the external one. Your reader already has access to your record. They can see your title, your tenure, and probably your last review. Re-narrating your career at them wastes the half page you have. What they do not know, and what they are actually reading for, is why you want to move, what you would bring on day one, and whether taking you would blow up the team you are leaving.
So answer those three things and stop. Why this team, in a sentence that shows you understand what they are trying to do. What you carry over, framed as the specific work of the new role rather than a list of your old one. And how the handover goes, which is the paragraph that quietly convinces a manager that you are safe to hire, because internal moves die on the fear of a mess left behind.
On politics: tell your current manager before the letter lands, or accept that they will find out from someone else and that this will cost you. Half a page is plenty. If your company runs a formal internal-mobility process, follow it exactly, and treat the letter as the thing that makes the form memorable rather than a way around it.
The mechanics
How long it should be, and the format questions everyone asks
The rest of the search results will not answer these plainly, so here they are.
Length
Roughly 250 to 350 words
Three or four short paragraphs. Nobody asked for this letter, which means the reader is doing you a favor by opening it, and length is how you repay that favor or squander it.
Pages
One page. Never two
A second page on an unsolicited letter reads as an inability to edit. If you cannot make the argument in one page, the argument is not ready, and adding words is not going to rescue it.
Put it in the body
Yes, a letter of interest can be an email, and it usually should be. Paste the text straight into the message. Attaching a PDF asks the reader to open a file from a stranger, which many will simply not do.
Signature
Typed name is fine
In an email, your name and a link under the sign-off is a complete signature. Nobody expects a scanned handwritten one, and pasting an image of your signature into an email tends to look stranger than it does formal.
Binding
It commits you to nothing
A letter of interest for a job has no legal force. You are not obliged to accept anything and neither are they. The document people are thinking of when they ask this is the letter of intent, which is a different thing.
Follow-up
One nudge, then move on
Wait seven to ten days, send one short reply on the same thread, then let it go. Silence to an unsolicited email is not a rejection, it is just a busy person, and a third message converts nothing.
The system
The hard part is sending the tenth one
Writing one good letter of interest is not difficult. Writing the tenth, after the first six went unanswered, is where almost everyone quits, and it is also the point at which this channel starts to work. Unsolicited letters have a low hit rate by construction, because you are asking for something that was never on offer. The compensation is that when one does land, you are the only candidate in the conversation, and there is no stack of applicants to be compared against.
That makes consistency the real skill, and consistency is mostly a tooling problem. If every letter starts from an empty document you will write three of them and stop. If it starts from a profile you have already filled in, with your roles, your outcomes, and your numbers sitting there ready, the marginal cost of the next letter is the fifteen minutes of research it deserves and nothing more.
That is the part Folio takes off you. Your profile builds the letter, you supply the company and the reason, and you pick the register you want from five tones. Leave the role blank and the letter is written for a company rather than a posting, which is exactly what this document is. Export it as PDF or DOCX at no cost on the free plan, with no watermark on the file. Free does have real limits and they are worth knowing before you start: no custom domain, so your site lives at portfolio.wrxstack.com and not at your own name, a small "Made with Folio" mark on the page, and ten AI drafting generations a month. The exports are not the thing being sold. The domain is.
Frequently asked questions
What is a letter of interest?
It is a message you send to an employer who has not advertised the job you want, explaining who you are and what you could do for them. Because there is no listing to answer, you propose the role yourself and argue that it is worth creating. It is also called a letter of inquiry, an expression of interest, or a prospecting letter.
Is a letter of interest the same as a cover letter?
No, though they are close relatives. A cover letter answers a specific advertised opening and matches your record against the requirements that were listed. A letter of interest goes out when nothing is posted, so it has to name a problem the company has and propose work you could do about it. Same tone, different job to do.
Who do you address a letter of interest to?
The person who would manage you. Recruiters work from open requisitions and yours does not exist, so a manager is the only reader who can act on it. Look at the team page, blog bylines, and conference talks to find a name. If nothing turns up, write "Dear Hiring Team," and never "To Whom It May Concern".
What should a letter of interest include?
Six things: a subject line that names the team and the topic, an opening sentence that says why you are writing to them specifically, one outcome from your record with a number attached, a two-line sketch of the role you are proposing, a small and specific ask, and a signature with one link that shows the work.
How long should a letter of interest be?
One page, three or four paragraphs, somewhere around 250 to 350 words. Nobody requested this letter, so brevity is the price of being read. If your case does not fit on a page, the case is not sharp enough yet and more words will not fix that.
How do you write a letter of interest for an internal position?
Skip your work history, because the reader can already see it. Cover three points instead: why you want that team, what you would bring to the specific work of the new role, and how your current responsibilities get handed over cleanly. Keep it to half a page, and tell your manager before it lands rather than after.