In the competitive world of SBIR and STTR funding, strong technical merit alone often isn’t enough. Reviewers are increasingly focused on a proposal’s commercial viability—and one of the most effective ways to demonstrate that potential is through well-chosen letters of support. While not mandatory, these endorsements offer credible, third-party validation that your innovation addresses a genuine need and that real-world stakeholders are paying attention.
Letters of support can reassure reviewers that your team is not developing technology in a vacuum. They signal that your solution is aligned with market demands and that trusted partners, customers, or investors are willing to engage. For both Phase I and Phase II proposals, thoughtful letters can tip the scale between a fundable and unfundable score.
Why Letters of Support Matter
Letters of support serve as powerful external validation in SBIR proposals. When written by credible third parties, they provide clear signals that your innovation solves a real problem and that stakeholders outside your company see its value. This external perspective is especially important for reviewers who may not be familiar with your specific market.
These letters also show that you’re actively engaged in your industry ecosystem—not just technically capable, but commercially aware. A strong letter might mention a stakeholder’s willingness to pilot your solution, partner on product development, or even consider a future purchase. That kind of real-world interest adds weight to your commercialization plan and helps distinguish your proposal from others.
Because commercialization potential is one of the three core evaluation criteria for SBIR awards, any credible evidence that supports it—like letters from future customers or collaborators—can make a meaningful difference in your score.
Who Makes the Strongest Supporters?
Not all letters of support carry the same weight. The most impactful endorsements come from people or organizations who can speak directly to the market potential of your innovation. Their credibility and proximity to your target audience make their support more persuasive to reviewers.
Potential customers or end-users are often the strongest voices. If someone who might actually buy or use your product confirms there’s a need—and expresses interest in testing or adopting your solution—it sends a compelling message. Similarly, strategic partners who could help distribute, co-develop, or scale your product bring practical relevance to your proposal.
Investors are another valuable source. If they’ve shown interest in providing future funding or are already engaged with your company, their support indicates commercial viability. Letters from industry-recognized experts or thought leaders can also be useful—especially when they address not just technical merit but the broader value of your solution.
What’s less useful? Vague letters that simply praise your technology without mentioning a market, customer, or real-world application. Academic endorsements that don’t speak to commercialization often fall flat unless paired with other, more market-oriented voices.
Note:
Generic letters that only praise your science—without referencing the market—rarely help your commercialization score.
What Makes a Letter Effective?
A strong letter of support does more than express enthusiasm—it connects your innovation to a tangible, real-world outcome. The best letters are clear, specific, and tailored to your project. They show that the writer understands what you’re doing, why it matters, and how they plan to engage with your technology.
Effective letters often explain the problem the supporter faces and how your solution addresses it. They might include statements of intent—such as participating in a pilot program, co-developing features, or providing a test environment. Even if non-binding, these commitments signal genuine interest.
The writer’s background also matters. A brief note on their qualifications or market position helps establish their credibility. Letters should align with your overall commercialization story, reinforcing your claims about target users, go-to-market strategy, or technical feasibility.
Avoid boilerplate language. Letters that feel templated or vague won’t move the needle with reviewers. Instead, coach your supporters to be direct about what they find compelling and how they see themselves involved.
Tip:
Don’t submit generic letters—ask supporters to be specific about how they would benefit from or work with your innovation.
How Many Letters Should You Include?
The right number of letters depends on which SBIR phase you’re applying for and the policies of the agency you’re targeting. In general, Phase I proposals benefit from two to three letters of support. These should come from stakeholders who understand the problem you’re solving and can speak to their interest in a future relationship.
For Phase II proposals, a larger set—typically four to five letters—is recommended, provided the agency allows it. At this stage, reviewers expect more evidence that you’re building real-world traction, so each letter should deepen the case for market readiness.
Always check agency-specific rules. Some agencies, like the National Science Foundation, place strict limits on the number or type of letters you can include. Others may allow more flexibility, especially for proposals with strong commercialization components.
Quality outweighs quantity. A handful of well-targeted, specific endorsements will do far more for your score than a stack of generic letters.
Practical Tips for Requesting and Structuring Letters
Getting strong letters of support takes more than just asking—how you approach your supporters can make or break the quality of the endorsement. Start by identifying individuals or organizations that are strategically aligned with your commercialization plan, then make the process as easy as possible for them.
First, provide context. Share a short summary of your project, what stage you’re in, and what kind of involvement (if any) they’ve already had. Then, offer bullet points or a draft they can customize—highlight the specific points you’d like them to address, such as market need, intent to collaborate, or product interest.
Be clear on the timeline. Many SBIR applicants underestimate how long it can take to secure thoughtful letters. Reach out at least three to four weeks before your submission deadline to give supporters time to write something meaningful.
It’s also helpful to follow up. A polite reminder a week before the deadline, along with a copy of your proposal’s executive summary, can go a long way in keeping your request on their radar.
Tip:
Start requesting letters 3–4 weeks before your deadline to give supporters time to write a quality endorsement.