Sizle integrates Lumin Sign to enable seamless signing

Sizle is a document CRM that helps organizations share, track, and sign mission-critical business documents with complete visibility. Used across fundraising, partnerships, charitable initiatives, and enterprise transactions, Sizle provides contextual engagement insights that drive faster completion cycles and smarter decisions.

When Sizle set out to add eSignature capabilities to their platform, they looked at different partners to find the right fit. They chose Lumin Sign's API, and the results speak for themselves.

The challenge: Removing friction from business documents

Sizle's customers use the platform for a range of documents and agreements. But the signing step always meant context switching, sending users to separate platforms, losing momentum, and introducing unnecessary complexity.

"We needed signing to feel native to Sizle," says Jeremy Duff, Founder & CEO of Sizle. "Our users shouldn't have to think about which tool does what. They should be able to move from tracking a proposal to collecting signatures without ever leaving the flow."

The challenge was finding an eSignature solution that could scale with their needs and feel like a natural extension of Sizle's offering.

Why Sizle chose Lumin Sign

Lumin Sign's infrastructure proved robust enough to handle Sizle's growing user base without introducing service interruptions.

The API documentation was clear, the endpoints were well-designed, and the authentication model aligned perfectly with Sizle's security requirements. Plus, unlike some enterprise-focused competitors, Lumin Sign delivered an interface optimized for speed and simplicity, ideal for Sizle's customers who value efficiency over feature bloat.

"Lumin provides the secure, scalable signing infrastructure that enables Sizle users to move from document share to completed agreement in a single flow," Duff explains. "Its reliability and ease of integration aligned with our focus on reducing friction and shortening the path from intent to signature."

How it works for users

The Lumin Sign integration creates a seamless experience from document sharing to final signature. When a Sizle user is ready to collect signatures, they click "Sign" directly within their document view. Behind the scenes, Sizle uploads the document to Lumin under the authenticated user's identity, creating a signature request without requiring any additional logins.

Once the signature request is sent, Sizle displays live status updates showing when recipients view the document, when they sign, and when the agreement is complete, all within the Sizle interface.

When all parties have signed, the fully executed document (including the Certificate of Completion) is automatically available for download. Users maintain full visibility without bouncing between platforms.

The technical implementation uses secure authentication and ensures every document is stored securely.

The results: Speed, confidence, and clarity

Since launching the Lumin Sign integration, Sizle has transformed how its customers complete agreements:

• Faster turnaround: By eliminating the friction of switching between tools, customers, whether closing funding rounds, finalizing partnership agreements, or securing grant commitments, report significantly shorter completion cycles.
• Reduced context switching: Keeping users in a single interface from share to signature has improved both productivity and user satisfaction.
• Greater confidence: The combination of Sizle's engagement analytics and Lumin's legally binding eSignatures gives teams unprecedented visibility into the entire document lifecycle, from initial view to final execution.

"Customers can now progress from sharing to legally binding signature in one seamless, trackable experience," Jeremy notes. "The result is faster turnaround, less context switching between tools, and greater confidence when completing agreements across teams."

The future of digital agreements

The Sizle-Lumin partnership represents a broader shift in how organizations approach digital agreements. By combining Sizle's document intelligence with Lumin's signing capabilities, the integration delivers one of the fastest agreement experiences available today.

As both platforms continue to evolve, with Lumin expanding into verified eSigning and digital trust infrastructure, the partnership creates new opportunities to enhance trust and verification throughout the entire agreement lifecycle.

"Working with Lumin allows us to remove one more layer of friction between teams and completed agreements," says Jeremy. "It's a simple improvement that compounds efficiency, trust and clarity for every user."

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