# Fifteenth

**Canonical:** https://apis.io/providers/fifteenth/  
**Website:** https://www.fifteenth.com/  
**APIs profiled:** 0

Fifteenth is a San Francisco-based fintech company operating an AI-powered personal tax platform for ambitious earners — founders, investors, executives, and technology professionals with complex financial situations such as equity compensation (ISOs, RSOs, RSUs, NSOs), liquidity events (IPOs and acquisitions), partnership income (K-1s), and active stock and crypto trading. The service pairs dedicated human CPAs with AI-driven automation: users link their banking, payroll, and investment accounts via one-click integrations (Workday, Rippling, Robinhood, Wealthfront, Carta, Charles Schwab, AngelList, Coinbase and more), and the platform automatically detects tax-relevant transactions, organizes documents, models scenarios, and delivers proactive quarterly planning plus unlimited year-round advice at flat-fee pricing starting around $1,000 per year. Fifteenth raised $8.25M in seed funding (February 2025) led by A* and General Catalyst. It is a consumer-facing product with no public developer API surface; this profile captures its identity and public web properties.

## Kin Score — 16.9 / 100 (emerging)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 16.9).

| Facet | Score |
|---|---|
| Discoverability | 50.0 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 0.0 |
| Developer Ergonomics | 7.1 |
| Commercial Clarity | 52.6 |
| Access Clarity | 52.6 |

## Agent readiness — 0.0 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## Security (1)

- **Fifteenth Domain Security** — TLSv1.3 · HSTS · DMARC

## Tags

Company, Fintech, Taxes, Tax Preparation, Tax Planning, Personal Finance, Equity Compensation, Accounting, Artificial Intelligence

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/fifteenth/). Scores are computed from the provider's own public artifacts under a published rubric.