Sales startup Letter AI snags $40 million Series B four months after its last raise. Read its pitch deck.

Letter AI has raised $40 million and is now valued in the hundreds of millions.
The sales software startup uses AI to deliver real-time, deal-specific guidance.
It secured back-to-back funding rounds amid rapid revenue growth, its CEO, Ali Akhtar, said.

Y Combinator startup Letter AI has raised $40 million in fresh funding just four months after its $10.6 million Series A, underscoring investor appetite for AI tools to reshape sales.

The Chicago-based startup's post-money valuation is now in the hundreds of millions of dollars, Letter cofounder and CEO Ali Akhtar told Business Insider.

Akhtar says companies have long relied on disparate tools for tasks such as sales content, training, and buyer engagement. Letter's software unites these systems into a single "command center," Akhtar said, displacing other tools and enabling sellers to spend more time interacting with customers.

Alongside announcing the Battery Ventures-led Series B, the company is also rolling out Letter Compass, a new product that provides personalized, deal-specific guidance during sales, including coaching tailored to a specific employee or opportunity and suggestions for messaging and next steps.

Akhtar said Battery approached him and cofounder Armen Forget, the CTO, about funding. He attributed the quick succession of rounds to "phenomenal traction" and retention. Y Combinator, Lightbank, Northwestern Mutual Future Ventures, and Stage 2 Capital also participated in the Series B alongside existing investors.

Letter counts customers across 30 countries, including Lenovo, Adobe, Novo Nordisk, and Plaid. It will use the funding to expand product development and grow the team globally — which counts 25 employees — across sales, engineering, and customer success, Akhtar said.

Letter is growing in a crowded field, as stalwarts like Salesforce increasingly incorporate AI features and sales AI startups emerge. Gong analyzes sales interactions, for instance, while Seismic and Highspot, which help train salespeople, have announced plans to merge.

Here's a look at the pitch deck Letter AI used to raise its $40 million Series B. Some slides have been removed so that the deck can be shared publicly.