United States · 
Who invested in Heirloom?
Heirloom's investors include Breakthrough Energy, Lowercarbon Capital, Ahren Innovation Capital, Carbon Direct Capital and Seven Seven Six, and 15 more on record.
202320242025
$53MSeries A$150MSeries B?VentureUnited States · Venture startup
Who invested in Heirloom
3 rounds we have observed, with the 20 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.
Follow Heirloom and see its new rounds in your feed. Start following
Funding summaryUpdated 5 Nov 2026
$203Mraised across 3 rounds since 2022, from 4 sources
$53MSeries A$150MSeries B
- Latest round
- VentureFeb 2025
- Biggest round
- $150MSeries B · Dec 2024
- Investors
- 20 (5 led)
The funding story
Each circle is a round, placed by date and sized by amount. The line above is the running total.
- First round
- Series A, $53M Mar 2022
- Biggest round
- $150M Series B · Dec 2024
- Usual gap between rounds
- 2.8 years the median of 2
The rounds
- Feb 2025VentureAmount undisclosed2 new3 returning
Source recorded
- Dec 2024Series B$150M8 new4 returning
Lowercarbon CapitalLead
Future PositiveLead
Breakthrough Energy
Mitsui & CoAtalanta Therapeutics
Siemens Financial Services
Ahren Innovation Capital
Carbon Direct Capital
MOL Switch LLC
Japan Airlines
MCJ Collective
Quantum Innovation Fund
Reported by Crunchbase News and 1 other
- Mar 2022
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.
Everyone who backed them
The Microsoft Climate Innovation FundVC firm1round
Missing a round, or an investor who was in one? Tell us.
Quick answers about Heirloom
How much has Heirloom raised?
Heirloom has raised $203M across 3 rounds since 2022. One round did not disclose an amount, so the total is a floor.
When did Heirloom last raise?
Heirloom's most recent round was a Venture in Feb 2025.
What was Heirloom's biggest round?
Heirloom's largest round on record is $150M (Series B), in Dec 2024, led by Lowercarbon Capital.
Who backed Heirloom first?
Heirloom's first round on record, in Mar 2022, was backed by Breakthrough Energy, Ahren Innovation Capital and Carbon Direct Capital and 7 others.
What stage is Heirloom at?
Heirloom's latest named round is a Venture, in Feb 2025.
Where is Heirloom based?
Heirloom is based in the United States.
Who led Heirloom's rounds?
Breakthrough Energy led the Series A in 2022; Lowercarbon Capital led the Series B in 2024.
Companies like Heirloom
In the same sector, and raised in the last eighteen months.
Find investors like these
Search every investor by what they have actually funded, then narrow to your stage and market. Free.