Letter of Inquiry for Grants: Format & Timing

A letter of inquiry (LOI) — sometimes called a letter of interest, concept letter, or pre-proposal — is a brief, unsolicited-style document a prospective grantee sends to a funder to gauge interest in a project idea before investing the time to prepare a full proposal. It is standard practice among private, family, community, and corporate foundations, and it exists to save both sides work: the funder screens far more ideas than it can fund without reading full applications for each one, and the applicant avoids writing a complete proposal for a project the funder was never going to support.

An LOI is not a full grant application. It typically does not include a detailed budget, full organizational financials, letters of support, or a complete project narrative. Its only job is to answer one question for the funder’s program staff: is this project close enough to our priorities, feasible, and credible enough to be worth inviting a full proposal?

Letter of inquiry vs. letter of intent: two different mechanisms

“Letter of inquiry” and “letter of intent” are often used loosely as synonyms, but on the funder side they describe genuinely different mechanisms depending on who is asking for one, and conflating them is a common source of confusion for research administrators moving between foundation and federal grantsmanship:

Foundation letter of inquiry (this page) — a competitive, evaluative document. The funder reads it and decides whether to invite a full proposal or decline. Content and framing matter; a weak LOI ends the process before a full application is ever written.
NSF Letter of Intent — a short, non-binding, administrative notice required only when a specific NSF program solicitation asks for one. It exists so NSF program officers can estimate proposal volume and line up enough qualified reviewers; it is not evaluated on merit and does not gate submission of the full proposal.
NIH Letter of Intent — historically a similar administrative, non-binding notice some NIH funding opportunities requested roughly 30 days ahead of a due date. NIH eliminated this requirement NIH-wide effective December 3, 2025 (Guide Notice NOT-OD-26-019, part of NIH’s administrative-burden-reduction effort); NIH no longer requests or reviews letters of intent as part of the standard application process.

The practical distinction to remember: a foundation LOI is a gate you must get through to be invited to apply at all, while a federal-agency letter of intent (where one is still requested) is a heads-up notice that does not itself decide whether you may submit. Don’t assume a solicitation’s silence on an “LOI” means no pre-application step is required — always read the specific funder’s guidelines, since terminology varies even among foundations.

Which funders require a letter of inquiry

LOI requirements are overwhelmingly a foundation-sector practice, not a federal one:

Private and family foundations — the most common users of a mandatory LOI stage, particularly larger foundations that receive far more applications than they can fund. Many private foundations do not accept unsolicited full proposals at all; an LOI (or, at some foundations, a nomination or invitation-only process) is the only entry point.
Community foundations — frequently use an LOI or a short online eligibility-screening form ahead of a full application, especially for competitive discretionary grant cycles.
Corporate foundations and corporate giving programs — commonly use a brief inquiry stage, often through an online form rather than a formal letter.
US federal agencies — do not use an “LOI” in the foundation sense. Where a federal solicitation includes a short pre-application step, it is typically a non-binding notice (an NSF Letter of Intent where a solicitation requires one) or a distinct instrument like a pre-proposal white paper, not a foundation-style competitive screening letter.
International and multilateral funders — practice varies widely by funder; check the specific program’s guidelines rather than assuming either a US-foundation-style LOI or a US-federal-style notice applies.

Always confirm on the funder’s own guidelines page or in the specific request for proposals whether an LOI is required, invited, or not used at all — foundations differ, and some accept full proposals directly on a rolling or scheduled basis with no LOI stage.

Typical letter of inquiry structure and required elements

Formats vary by funder, and some foundations provide a required template, an online form, or a strict outline that must be followed exactly — always defer to funder-specific instructions over any general structure. Where no specific format is dictated, a foundation LOI conventionally covers:

Introduction — your organization’s name and mission in one or two sentences, the program or project you are proposing, and the amount you intend to request.
Statement of need — the problem the project addresses, ideally grounded in one or two concrete data points rather than general assertions. See Statement of Need: Examples and How to Write One for how this section is typically constructed in a full proposal; an LOI version is a compressed version of the same logic.
Project description — what you will actually do: target population or scope, key activities, and the approximate timeframe. This is deliberately concrete but brief — an LOI is not the place for a full methods section.
Expected outcomes — what will change or be produced as a result, stated in terms the funder can evaluate for fit with its own priorities.
Alignment with the funder’s priorities — an explicit, specific connection between the project and the funder’s stated mission or current funding priorities, not a generic claim of fit.
Brief organizational credibility statement — why your organization (or research team/institution) is positioned to carry out the work.
Budget summary — the total amount requested and, often, a one- or two-line breakdown of major cost categories. A full itemized budget is not expected at this stage.
Closing and contact information — a brief statement of appreciation and the name, title, and contact details of the person the funder should reach for follow-up.

Many foundations also expect the LOI to be signed by, or submitted alongside a brief note from, an institutional authorized official (for a university-based project, typically the sponsored programs or foundation relations office), since it is effectively the applicant’s first formal representation to the funder.

Length norms

Foundation LOIs run short by design: commonly one to two pages, with some funders capping submissions at a strict page or word limit (or a fixed-field online form that enforces the limit structurally). Foundation program staff routinely review large volumes of inquiries in a single cycle, so length itself is part of what is being evaluated — a letter that cannot state the case concisely reads as a weaker submission independent of the underlying project’s merit. Where a funder does not publish an explicit limit, one to two pages is the safest default; exceeding roughly three pages is unusual and, absent explicit funder instructions calling for more, risks signaling that the applicant hasn’t distilled the project to its essentials.

What happens after you submit

Foundations typically respond to an LOI in one of three ways:

Invitation to submit a full proposal — the funder found sufficient fit and merit to warrant a complete application, which then goes through the funder’s standard review process. An invitation is not a funding commitment; it only means the project has cleared the initial screen.
Request for revision or additional information — some funders ask for a revised LOI, a clarifying call, or supplementary material before deciding whether to invite a full proposal.
Decline — the funder determines the project is not a fit, often for reasons of budget capacity, current funding priorities, or geographic/program restrictions rather than project quality alone. Most foundations that decline at the LOI stage do not provide detailed individualized feedback, given the volume of inquiries reviewed; a short, professional reply requesting any available feedback is reasonable, but a lengthy rebuttal or appeal is not standard practice.

Response timelines vary substantially by funder — anywhere from a few weeks to several months — and are typically published in the funder’s own guidelines or grant cycle calendar; when a funder does not state a timeline, a polite status inquiry after the published or typical review window has passed is appropriate. Only a minority of LOIs submitted in a given cycle are typically invited to submit a full proposal, reflecting the LOI stage’s actual purpose as a competitive screen rather than a formality — treat an invitation to submit a full proposal as a meaningful, but not final, step toward funding.

Common mistakes to avoid

Treating the LOI as a shortened version of a full proposal rather than its own document — cramming in every detail meant for the full application makes the LOI too long and buries the elements the funder actually needs to make a screening decision.
Generic priority-alignment language — asserting fit with the funder’s mission without naming the specific program area, prior grants, or published priority the project actually connects to.
Skipping the funder’s own template or instructions when one is provided, in favor of a generic house LOI format.
Omitting a specific dollar amount — vague requests (“we welcome any support”) make it harder for a funder to assess fit against its typical grant size.
Sending the same LOI to every funder unmodified — foundations can generally tell, and a letter that reads as a form letter rather than a genuine fit assessment weakens the case.

Frequently asked questions

Is a letter of inquiry the same as a letter of intent?

Not exactly, though the terms are often used loosely. A foundation letter of inquiry is a competitive, evaluated document that determines whether you are invited to submit a full proposal. A federal-agency letter of intent — where one is still required, such as under some NSF program solicitations — is typically a short, non-binding administrative notice used for review-planning purposes and does not itself gate submission. Always check the specific funder’s own terminology and requirements rather than assuming which meaning applies.

How long should a letter of inquiry be?

Most foundation LOIs run one to two pages. Some funders publish a strict page or word limit, or use a fixed-field online form; follow that limit exactly. Where no limit is published, one to two pages is a safe default.

Do federal grants like NIH and NSF require a letter of inquiry?

No — US federal agencies do not use a foundation-style letter of inquiry. NSF requires an NSF Letter of Intent only for specific program solicitations that ask for one, and it is a non-binding notice rather than a competitive screen. NIH eliminated its letter-of-intent process NIH-wide effective December 3, 2025.

What happens if my letter of inquiry is declined?

The project is not invited to submit a full proposal to that funder in that cycle. Most foundations do not give detailed individualized feedback given the volume of inquiries they review. A decline at the LOI stage does not necessarily reflect on project quality — it often reflects capacity, current priorities, or fit rather than merit alone — and reapplying in a future cycle, or to a different funder whose priorities align more closely, is common practice.

Can I submit a full proposal without an LOI being requested?

Only if the funder’s guidelines say so. Many foundations that use an LOI stage do not accept unsolicited full proposals at all outside that process, so submitting a full proposal uninvited typically will not be reviewed. Always follow the specific funder’s stated submission process.