Column Tax

Column Tax is an IRS-authorized, API-first tax filing platform that lets banks, brokerages, neobanks, and SMB/freelancer fintech apps embed a full white-label income-tax preparation and e-file experience directly inside their own product. Partners create a Column Tax user via a server-side REST call, receive a short-lived authenticated URL, and launch the Column Tax UI (web loader or native iOS, Android, and React Native SDKs) embedded in their app, while webhooks report each user through the filing lifecycle. Column Tax offers DIY Filing and Expert Review products, is a SOC 2-certified and IRS-authorized e-file provider, and reports outcomes such as higher retention and direct-deposit switching for embedded partners.

Column Tax publishes 1 API on the APIs.io network. Tagged areas include Company, Fintech, Tax, Tax Filing, and Embedded Finance.

The Column Tax catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Column Tax’s developer surface includes documentation, API reference, getting-started guide, quickstart, authentication, support, engineering blog, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub

40.0/100 developing ▬ flat Agent 23/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

1 APIs

Company Fintech Tax Tax Filing Embedded Finance E-File Financial-Services Banking API-First

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 40.0/100 · developing

Contract Quality 8.8 / 21

Developer Ergonomics 7.9 / 17

Access Clarity 4.9 / 17

Operational Transparency 2.0 / 11

Contract Governance 1.9 / 10

Discoverability 6.5 / 9

Regulatory Posture 7.0 / 15

Agent readiness — 23/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 6 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Banking & Open Finance regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/column-tax: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

Column Tax API

REST API to embed IRS-authorized income-tax preparation and e-filing. Create a Column Tax user, obtain a short-lived authenticated URL to launch the embedded filing UI, list a u...

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Column Tax Webhooks

ASYNCAPI

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Column Tax Authentication

http · 1 scheme

SECURITY

Column Tax Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

Quickstart

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

X-MCPServerCandidate

X-MCPServerCandidate

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

Conformance

Webhooks

DataModel

Components

Scroll for all 7

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

SDKs

SDKs

Access & Security 4

Authentication, authorization, and security posture

DomainSecurity

Authentication

Authentication

Compliance

Operate 2

Status, limits, changes, and where to get help

Support

Support

StatusPage

StatusPage

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: column-tax
name: Column Tax
description: Column Tax is an IRS-authorized, API-first tax filing platform that lets banks, brokerages, neobanks, and SMB/freelancer
  fintech apps embed a full white-label income-tax preparation and e-file experience directly inside their own product. Partners
  create a Column Tax user via a server-side REST call, receive a short-lived authenticated URL, and launch the Column Tax
  UI (web loader or native iOS, Android, and React Native SDKs) embedded in their app, while webhooks report each user through
  the filing lifecycle. Column Tax offers DIY Filing and Expert Review products, is a SOC 2-certified and IRS-authorized e-file
  provider, and reports outcomes such as higher retention and direct-deposit switching for embedded partners.
url: https://raw.githubusercontent.com/api-evangelist/column-tax/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  - sandbox
  generated: '2026-09-03'
  method: derived
image: https://cdn.prod.website-files.com/6262ffa3aeadc15ee876298b/627bf917c708fc0ec6460fcb_Text_Image.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- bain-capital-ventures
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-18'
tags:
- Company
- Fintech
- Tax
- Tax Filing
- Embedded Finance
- E-File
- Financial-Services
- Banking
- API-First
tags_raw:
- Company
- Fintech
- Tax
- Tax Filing
- Embedded Finance
- E-File
- Financial Services
- Banking
- API First
apis:
- name: Column Tax API
  description: REST API to embed IRS-authorized income-tax preparation and e-filing. Create a Column Tax user, obtain a short-lived
    authenticated URL to launch the embedded filing UI, list a user's tax returns and jurisdictions, and subscribe to webhook
    events across the filing lifecycle.
  humanURL: https://docs.columntax.com/v1.1/reference
  baseURL: https://prod.columnapi.com
  tags:
  - Tax
  - E-File
  - Embedded Finance
  properties:
  - type: Documentation
    url: https://docs.columntax.com/docs/welcome
  - type: APIReference
    url: https://docs.columntax.com/v1.1/reference
  - type: Authentication
    url: https://docs.columntax.com/reference/authentication
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/column-tax-domain-security.yml
- type: Website
  url: https://www.columntax.com/
- type: DeveloperPortal
  url: https://docs.columntax.com/docs/welcome
- type: Documentation
  url: https://docs.columntax.com/docs/welcome
- type: APIReference
  url: https://docs.columntax.com/v1.1/reference
- type: GettingStarted
  url: https://docs.columntax.com/docs/quick-start
- type: Quickstart
  url: https://docs.columntax.com/docs/quick-start
- type: Authentication
  url: https://docs.columntax.com/reference/authentication
- type: Support
  url: https://www.columntax.com/contact-us
- type: Blog
  url: https://www.columntax.com/blog
- type: GitHubOrganization
  url: https://github.com/column-tax
- type: StatusPage
  url: https://status.columntax.com
- type: TermsOfService
  url: https://www.columntax.com/terms-of-use
- type: PrivacyPolicy
  url: https://www.columntax.com/privacy-policy
- type: Packages
  url: packages/column-tax-packages.yml
- type: SDKs
  url: packages/column-tax-packages.yml
- type: LLMsTxt
  url: llms/column-tax-llms.txt
- type: Authentication
  url: authentication/column-tax-authentication.yml
- type: Conventions
  url: conventions/column-tax-conventions.yml
- type: ErrorCatalog
  url: errors/column-tax-problem-types.yml
- type: Lifecycle
  url: lifecycle/column-tax-lifecycle.yml
- type: Conformance
  url: conformance/column-tax-conformance.yml
- type: Compliance
  url: conformance/column-tax-conformance.yml
- type: X-MCPServerCandidate
  url: mcp/column-tax-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: Sandbox
  url: sandbox/column-tax-sandbox.yml
- type: Webhooks
  url: asyncapi/column-tax-webhooks.yml
- type: DataModel
  url: data-model/column-tax-data-model.yml
- type: Components
  url: components/column-tax-components.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

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