# Callosum funding: rounds and investors > Callosum has raised $110M across 3 rounds since 2026. Investors include Charlie Songhurst, Atomico and DCVC. Every round with its source. Source: https://millionrounds.com/company/callosum (Millionrounds; every figure on the page links to its filing or article) United Kingdom · [Seed startup](https://millionrounds.com/companies) # Who invested in *Callosum* 3 rounds we have observed, with the 6 investors named in them. Every figure came from a named source, and where the company reported a raise to the SEC itself, that is shown beside it. AI Construction Raised 3 months ago Follow Callosum and see its new rounds in your feed. [Start following](https://millionrounds.com/login?join=1&why=follow&next=%2Fcompany%2Fcallosum) Funding summary Updated 5 Nov 2026 **$110M** raised across 3 rounds since 2026, from 8 sources **$10M** Pre-seed **$100M** Seed - **Latest round:** Seed, $100M Aug 2026 - **Led by:** Atomico - **Step-up i:** 9.7× - **Investors:** 6 (1 led) See who backed them ## The funding story Each circle is a round, placed by date and sized by amount. The line above is the running total. 2027 **$10M** Pre-seed **?** Venture **$100M** Seed - **First round:** Pre-seed, $10M - **Biggest round:** $100M - **Usual gap between rounds:** 5 months ## The rounds - **Aug 2026** Seed **$100M** *5 new* [Atomico](https://millionrounds.com/fund/atomico) Lead [DCVC](https://millionrounds.com/fund/data-collective) [AlbionVC](https://millionrounds.com/fund/albionvc) [Plural](https://millionrounds.com/fund/plural) [UK Sovereign AI Fund](https://millionrounds.com/fund/uk-sovereign-ai-fund) Reported by AlbionVC and 5 others - **Apr 2026** Venture **Amount undisclosed** *1 returning* [Charlie Songhurst](https://millionrounds.com/fund/charlie-songhurst) Source recorded - **Feb 2026** Pre-seed **$10M** *1 new* [Charlie Songhurst](https://millionrounds.com/fund/charlie-songhurst) Source recorded ## Founders and team From Callosum's own website: 2 founders, 4 on the team. **Danyal Akarca** Co-founder **Jascha Achterberg** Co-founder - **James Chalmers** Head of Ecosystem and Partnerships - **Ragav Manimaran** Head of US - **Benedetta Gaggio** General Manager - **Natalie Wallis** Operations Manager ## Who was in which round The busiest backers across the latest rounds. A filled square is a round they joined; a dark one, a round they led. **Pre-seed** 2026 **Venture** 2026 **Seed** 2026 [Charlie Songhurst](https://millionrounds.com/fund/charlie-songhurst) [Atomico](https://millionrounds.com/fund/atomico) L [DCVC](https://millionrounds.com/fund/data-collective) [AlbionVC](https://millionrounds.com/fund/albionvc) [Plural](https://millionrounds.com/fund/plural) [UK Sovereign AI Fund](https://millionrounds.com/fund/uk-sovereign-ai-fund) ## Everyone who backed them [Charlie Songhurst](https://millionrounds.com/fund/charlie-songhurst) VC firm **2** rounds [Atomico](https://millionrounds.com/fund/atomico) VC firm **1** round, led 1 [DCVC](https://millionrounds.com/fund/data-collective) VC firm **1** round [AlbionVC](https://millionrounds.com/fund/albionvc) VC firm **1** round [Plural](https://millionrounds.com/fund/plural) VC firm **1** round [UK Sovereign AI Fund](https://millionrounds.com/fund/uk-sovereign-ai-fund) VC firm **1** round Missing a round, or an investor who was in one? [Tell us](https://millionrounds.com/corrections?slug=callosum). ## Also claim to have backed them These 6 firms list Callosum as a portfolio company on their own websites, but no report of a round names them. They are the firms' own claims, kept apart from the rounds above. [Samos Investments](https://millionrounds.com/fund/samos-investments-2) VC firm Per its own site [Sovereign AI](https://millionrounds.com/fund/sovereign-ai) Government Per its own site [Dunamu & Partners](https://millionrounds.com/fund/dunamu-and-partners) Corporate VC Per its own site [In This Together](https://millionrounds.com/fund/in-this-together) Family office Per its own site [Acclimate Ventures](https://millionrounds.com/fund/acclimate-ventures) VC firm Per its own site [Bare Metal Ventures](https://millionrounds.com/fund/bare-metal-ventures) VC firm Per its own site ## Quick answers about Callosum ### Who invested in Callosum? Callosum's investors include Charlie Songhurst, Atomico, DCVC, AlbionVC and Plural, and 1 more on record. Atomico led its latest round. ### How much has Callosum raised? Callosum has raised $110M across 3 rounds since 2026. One round did not disclose an amount, so the total is a floor. ### When did Callosum last raise? Callosum's most recent round was a Seed of $100M in Aug 2026, led by Atomico. ### What was Callosum's biggest round? Its most recent round, $100M in Aug 2026, is also its largest on record. ### Who backed Callosum first? Callosum's first round on record, in Feb 2026, was backed by Charlie Songhurst. ### What stage is Callosum at? Callosum's latest named round is a Seed, in Aug 2026. ### Where is Callosum based? Callosum is based in the United Kingdom. ### Who led Callosum's rounds? Atomico led the Seed in 2026. ## Companies like Callosum In the same sector, and raised in the last eighteen months. [**Atmospheric AI** $20M · Nov 2026](https://millionrounds.com/company/atmospheric-ai)[**Lazarus AI** $43M · Nov 2026](https://millionrounds.com/company/lazarus-ai)[**Crediflow AI** $2.0M · Nov 2026](https://millionrounds.com/company/crediflow-ai)[**Thistle** $10M · Nov 2026](https://millionrounds.com/company/thistle)[**Fractile** $960M · Oct 2026](https://millionrounds.com/company/fractile)[**Nexgen Cloud** $179M · Oct 2026](https://millionrounds.com/company/nexgen-cloud) ## Find investors like these Search every investor by what they have actually funded, then narrow to your stage and market. Free. Open the investor searchOr these rounds in the app