Prelude raises $20m Series A to fix broken SMS onboarding

Broken SMS onboarding hits companies at almost every level. 

Up to 30% of SMS verification codes are generated by fraudulent intermediaries: fake users, fake numbers, artificial traffic, all designed to pocket a portion of your SMS bill. And that’s before you factor in the real users churning at the OTP screen before they’ve ever seen your product.

Historically, there hasn’t been a real incentive for legacy providers to fix this. They tend to charge per SMS sent, not per successful verification. Failed codes, resends, pumping fraud – all of it generates more revenue for them. Prelude flips this model on its head. 

Today, we’re proud to see that Prelude is announcing a $20m Series A led by 20VC, with participation from us at Seedcamp, Singular and Deel. Their total funding now sits at $27m.

Prelude is the onboarding and trust infrastructure platform which verifies and protects users across their entire lifecycle. By combining a user’s telecom data, device intelligence, network signals, and behavioural patterns into a single trust profile, companies can get a comprehensive snapshot of who is using their product, all while improving conversion rates and user experience. In direct contrast to legacy providers, Prelude charges per verification, not per SMS sent, aligning their incentives directly with their customers.

Alongside the raise, the company is launching two new products: Auth API (continuous trust checks across the full user lifecycle) and Intel API (real-time carrier intelligence directly into onboarding flows). Together with its existing Verify API, Prelude now covers the full onboarding journey – from first signal to ongoing session behavior.

Since we first backed Prelude in 2024, it’s been incredible to watch the market respond to their momentum. Prelude’s revenue and customers have both grown by 6x in the past year, while customers have cut verification costs by over 40%. They’re already working with companies like Suno, BeReal, Voodoo, and Sunday to verify users and catch bots at scale.

Founders Matias Berny and Quentin Le Bras know this space intimately. The two met at Zenly, the popular location-sharing app with tens of millions of users that was acquired by Snap. Matias spent most of his three years there on SMS verification alone – what he initially thought would be a two-month fix ended up requiring a dedicated team. When they left Zenly, they decided to share what they’d learned with the world.

Prelude’s timing isn’t incidental. Bots are projected to represent more internet traffic than humans by 2027. AI agents are already infiltrating signup flows. Generative tools have made impersonation dramatically easier. The old playbook – one-time passwords, one static check – simply isn’t fit for purpose anymore.

Matias Berny, Cofounder and CEO, Prelude: “The old playbook is broken. CAPTCHAs don’t stop bots anymore, and a single fraud signal won’t tell you who’s really there. Telling a real user from a fake one is now a business intelligence problem, not a checkbox. The phone number is becoming the strongest anchor we have, and with the Intel API, it carries more trust than any password or one-time code ever did.”

Sia Houchangnia, Investor at Seedcamp, commented on the raise: “Matias and Quentin know this problem better than anyone else. They lived the pain of broken SMS verification at scale while at Zenly and saw that the incumbents were structurally misaligned with customers.”

“Prelude was built to fix that from the ground up, and the speed of execution since we led their pre-seed two years ago has been incredible. We’re excited to double down in this Series A led by our friends at 20VC as Prelude expands from verification into the broader trust layer every digital business will need in the AI age.”

We backed Matias and Quentin early because we believed they were the right people to rebuild onboarding from the ground up. This raise – and what they’ve built since – makes that case very clearly.