Callbook AI

Active · AI collections agency for late stage portfolios

Why it ranks

9signal of 100 · rising 9

A sum of public facts, not a judgement and not investment advice.

Companies closest to Callbook AI
Company	Category	Status	Program
Promoted.aiShared: late stageYC W21AcquiredAI	AI	Acquired	YCW21
CollectWiseShared: collection agencyYC F24ActiveAI	AI	Active	YCF24

Companies next to Callbook AI
Company	Category	Status	Program
DebtStreamShared: collection agencyAntler 2023Not statedOther	Other	Not stated	Antler2023
OncoboxShared: late stage, findingYC S17ActiveOther	Other	Active	YCS17
LEAH LabsShared: late stageYC W19ActiveOther	Other	Active	YCW19
GabbiShared: late stagePlug and Play Not statedOther	Other	Not stated	Plug and Play
ValidShared: agencyNeo Not statedAI	AI	Not stated	Neo

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6thSenseNervous System for Physical AIteam of 4ActiveAI	AI	Active
83 SciencesAI-native materials discovery powered by unpublished experimental datateam of 3hiringActiveAI	AI	Active
Agentcardlet agents buy anything onlineteam of 4ActiveAI	AI	Active
Agnost AIWe find where AI agents fail, then train better models to run them.2 programsteam of 2ActiveAI, Data, Devtools	AI, Data, Devtools	Active
Akon LabsDatabricks for Enterprise Codebasesteam of 2ActiveAI	AI	Active
Allia HealthAI-Native Medical Group for Mental Healthteam of 3hiringActiveAI	AI	Active

Callbook AI is a collections agency operated by AI. We collect late stage portfolios by finding, contacting and negotiating with borrowers.

YC tags: AI

Which YC batch was Callbook AI in?

Callbook AI was in Y Combinator's Summer 2026 batch (S26).

Is Callbook AI still active?

Y Combinator lists Callbook AI as active.

Who founded Callbook AI?

Callbook AI's founders, as listed on its YC page: Diego Avellaneda (Founder/CEO), Daniel Martinez (Founder & Product).

Where is Callbook AI based?

Callbook AI lists San Francisco, CA, USA; Remote as its location on YC's directory.