Form3 website screenshot

Form3

Form3 is a United Kingdom-headquartered, cloud-native payments technology company offering account-to-account payment processing as a single, unified REST API to banks and fintechs. Founded in 2016 and headquartered in London, Form3 runs a fully managed, Payments-as-a-Service platform that connects customers to domestic and cross-border schemes - UK Faster Payments, Bacs and CHAPS, SEPA Credit Transfer, SEPA Instant and SEPA Direct Debit, and US instant rails - alongside Confirmation of Payee / Verification of Payee name-checking, direct debit mandate management, scheme-addressable account identification, event notifications (webhooks), and full audit trails. Its public API is REST built on the json:api specification, documented at api-docs.form3.tech with a downloadable Swagger 2.0 definition, and authenticated with OAuth2 client-credentials plus HTTP Message Signatures request signing and, in some environments, mutual TLS. Form3 is API-native and developer-facing but is a regulated B2B rail rather than an open self-serve signup product; production access is contracted.

Form3 publishes 7 APIs on the APIs.io network, including Public API, Payments API, Direct Debits & Mandates API, and 4 more. Tagged areas include Payments, United Kingdom, Payment Processing, Account-to-Account, and Real-Time Payments.

The Form3 catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Form3’s developer surface includes authentication, changelog, documentation, API reference, getting-started guide, engineering blog, and 32 more developer resources.

🌐 Visit website 📡 Source on GitHub
53.6/100 developing ▬ flat Agent 47/100 agent native Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0
7 APIs 1 MCP Servers
PaymentsUnited KingdomPayment ProcessingAccount-to-AccountReal-Time PaymentsFaster PaymentsBacsSEPADirect DebitConfirmation of PayeeCross-BorderBanking-as-a-ServiceEmbedded Payments

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0
Composite quality — 53.6/100 · developing
Contract Quality 10.8 / 21
Developer Ergonomics 10.6 / 17
Commercial Clarity 6.3 / 17
Operational Transparency 6.1 / 11
Governance 1.2 / 10
Discoverability 7.9 / 9
Regulatory Posture 10.8 / 15
Agent readiness — 47/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 3 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Regulatory Posture applies to this provider. Its tags matched the Payments 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.
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/. This rating is computed from github.com/api-evangelist/form3: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 7

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

Form3 Public API

The unified Form3 Public API - a single REST API built on the json:api specification that connects banks and fintechs to domestic and cross-border payment schemes, covering paym...

Form3 Payments API

Send and receive account-to-account payments across supported schemes - UK Faster Payments, Bacs and CHAPS, SEPA Credit Transfer, SEPA Instant, and US instant rails - and handle...

Form3 Direct Debits & Mandates API

Originate and receive Bacs and SEPA direct debits, manage direct debit mandates, and process indemnity claims. Represented by the DirectDebits, DirectDebitsReads and Mandates op...

Form3 Account Identification & Verification API

Generate and manage scheme-addressable customer account numbers, validate UK sort code / account number combinations, and run Confirmation of Payee (UK) and Verification of Paye...

Form3 Files API

Submit and receive bulk payment instructions and scheme messages as files. Represented by the Transaction File API and Scheme File API operations under /files in the Form3 Publi...

Form3 Event Notifications API

Subscribe to and receive event notifications (webhooks) for payment and platform lifecycle events, and verify their signatures. Represented by the Subscriptions and notification...

Form3 Security & Access API

Manage users, roles, access-control entries and public keys under a flexible security and approval model, and read full audit trails and platform metrics. Represented by the Use...

Scroll for all 7

Postman Collections 1

Ready-to-run Postman collections for exercising this provider's APIs.

Form3 Public API

POSTMAN

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Form3 Public API

OPEN COLLECTION

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

form3-mcp.yml

MCP SERVER

Event Specifications 1

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

Form3 Notifications Webhooks

ASYNCAPI

Security Posture 4

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

Form3 Authentication

http/oauth2 · 2 schemes

SECURITY

Form3 Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Form3 Vulnerability Disclosure

security.txt · contact published

SECURITY

Form3 Trust Center

SOC 2, ISO 27001, ISO 27017, ISO 27018

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Form3 Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Form3 Agentic Access

205 operations · 84 acting · 2 human-in-the-loop

205 operations · 84 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted

Documentation 3

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference
 OpenAPI
OpenAPI

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess
 WellKnown
WellKnown
 MCPServer
MCPServer
 LLMsTxt
LLMsTxt
 AgentSkill
AgentSkill

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conformance
Conformance
 ErrorCatalog
ErrorCatalog
 Lifecycle
Lifecycle
 Conventions
Conventions
 Idempotency
Idempotency
 DataModel
DataModel
 Webhooks
Webhooks

Scroll for all 7

Build 5

SDKs, sample code, and the tooling you integrate with

PostmanWorkspace
PostmanWorkspace
 Packages
Packages
 SDKs
SDKs
 GitHubOrganization
GitHubOrganization
 Postman
Postman

Access & Security 8

Authentication, authorization, and security posture

TrustCenter
TrustCenter
 VulnerabilityDisclosure
VulnerabilityDisclosure
 DomainSecurity
DomainSecurity
 OAuthScopes
OAuthScopes
 Authentication
Authentication
 Security
Security
 Compliance
Compliance
 SecurityTxt
SecurityTxt

Scroll for all 8

Operate 2

Status, limits, changes, and where to get help

ChangeLog
ChangeLog
 StatusPage
StatusPage

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 3

The organization behind the API

Website
Website
 Blog
Blog
 LinkedIn
LinkedIn

Other 1

Properties that don't map to a standard resource type

Overlay
Overlay

Source (apis.yml)

apis.yml Raw ↑ 
aid: form3
url: https://raw.githubusercontent.com/api-evangelist/form3/refs/heads/main/apis.yml
name: Form3
kind: company
description: Form3 is a United Kingdom-headquartered, cloud-native payments technology company offering account-to-account
  payment processing as a single, unified REST API to banks and fintechs. Founded in 2016 and headquartered in London, Form3
  runs a fully managed, Payments-as-a-Service platform that connects customers to domestic and cross-border schemes - UK Faster
  Payments, Bacs and CHAPS, SEPA Credit Transfer, SEPA Instant and SEPA Direct Debit, and US instant rails - alongside Confirmation
  of Payee / Verification of Payee name-checking, direct debit mandate management, scheme-addressable account identification,
  event notifications (webhooks), and full audit trails. Its public API is REST built on the json:api specification, documented
  at api-docs.form3.tech with a downloadable Swagger 2.0 definition, and authenticated with OAuth2 client-credentials plus
  HTTP Message Signatures request signing and, in some environments, mutual TLS. Form3 is API-native and developer-facing
  but is a regulated B2B rail rather than an open self-serve signup product; production access is contracted.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Payments
- United Kingdom
- Payment Processing
- Account-to-Account
- Real-Time Payments
- Faster Payments
- Bacs
- SEPA
- Direct Debit
- Confirmation of Payee
- Cross-Border
- Banking-as-a-Service
- Embedded Payments
created: '2026-07-24'
modified: '2026-07-24'
specificationVersion: '0.19'
apis:
- aid: form3:form3-public-api
  name: Form3 Public API
  description: The unified Form3 Public API - a single REST API built on the json:api specification that connects banks and
    fintechs to domestic and cross-border payment schemes, covering payments, direct debits, mandates, accounts, files, notifications,
    security and audit. Swagger 2.0, 163 documented paths, host api.form3.tech, basePath /v1, OAuth2 client-credentials with
    HTTP Message Signatures request signing.
  humanURL: https://www.api-docs.form3.tech/
  baseURL: https://api.form3.tech/v1
  tags:
  - Payments
  - REST
  - json:api
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
  - type: GettingStarted
    url: https://www.api-docs.form3.tech/api/tutorials/getting-started/introduction
- aid: form3:form3-payments-api
  name: Form3 Payments API
  description: Send and receive account-to-account payments across supported schemes - UK Faster Payments, Bacs and CHAPS,
    SEPA Credit Transfer, SEPA Instant, and US instant rails - and handle payment exceptions such as rejections, returns,
    reversals and recalls. Represented by the PaymentReads and PaymentWrites operations under /transaction/payments in the
    Form3 Public API.
  humanURL: https://www.api-docs.form3.tech/api/tutorials/getting-started/send-a-payment
  baseURL: https://api.form3.tech/v1
  tags:
  - Payments
  - Faster Payments
  - SEPA
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/getting-started/send-a-payment
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/getting-started/receive-a-payment
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
- aid: form3:form3-direct-debits-mandates-api
  name: Form3 Direct Debits & Mandates API
  description: Originate and receive Bacs and SEPA direct debits, manage direct debit mandates, and process indemnity claims.
    Represented by the DirectDebits, DirectDebitsReads and Mandates operations under /transaction/directdebits and /transaction/mandates
    in the Form3 Public API.
  humanURL: https://www.api-docs.form3.tech/api/tutorials/bacs/direct-debit-instructions-for-originators
  baseURL: https://api.form3.tech/v1
  tags:
  - Direct Debit
  - Bacs
  - Mandates
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/bacs/receive-a-direct-debit
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
- aid: form3:form3-account-verification-api
  name: Form3 Account Identification & Verification API
  description: Generate and manage scheme-addressable customer account numbers, validate UK sort code / account number combinations,
    and run Confirmation of Payee (UK) and Verification of Payee name-checking. Represented by the AccountIdentification,
    AccountValidation, BranchIdentification and Name Verification operations under /transaction and /validations in the Form3
    Public API.
  humanURL: https://www.api-docs.form3.tech/api/tutorials/confirmation-of-payee/cop-tutorial
  baseURL: https://api.form3.tech/v1
  tags:
  - Confirmation of Payee
  - Account Validation
  - Identity
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/confirmation-of-payee/cop-tutorial
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
- aid: form3:form3-files-api
  name: Form3 Files API
  description: Submit and receive bulk payment instructions and scheme messages as files. Represented by the Transaction File
    API and Scheme File API operations under /files in the Form3 Public API.
  humanURL: https://www.api-docs.form3.tech/api/tutorials/bacs/send-transactions-in-a-file
  baseURL: https://api.form3.tech/v1
  tags:
  - Files
  - Bulk
  - Bacs
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/bacs/send-transactions-in-a-file
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
- aid: form3:form3-event-notifications-api
  name: Form3 Event Notifications API
  description: Subscribe to and receive event notifications (webhooks) for payment and platform lifecycle events, and verify
    their signatures. Represented by the Subscriptions and notification operations under /notification in the Form3 Public
    API.
  humanURL: https://www.api-docs.form3.tech/api/tutorials/event-notifications/subscriptions-for-event-notifications
  baseURL: https://api.form3.tech/v1
  tags:
  - Webhooks
  - Event Notifications
  - Subscriptions
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/event-notifications/subscriptions-for-event-notifications
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/event-notifications/verify-event-notifications
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
- aid: form3:form3-security-access-api
  name: Form3 Security & Access API
  description: Manage users, roles, access-control entries and public keys under a flexible security and approval model, and
    read full audit trails and platform metrics. Represented by the Users, Roles, ACE, Public Keys, Audit and Metrics operations
    under /security, /audit and /metrics in the Form3 Public API.
  humanURL: https://www.api-docs.form3.tech/api/tutorials/security/create-a-read-only-user
  baseURL: https://api.form3.tech/v1
  tags:
  - Security
  - Access Control
  - Audit
  properties:
  - type: OpenAPI
    url: openapi/form3-payments.yml
  - type: Documentation
    url: https://www.api-docs.form3.tech/api/tutorials/security/create-a-read-only-user
  - type: APIReference
    url: https://api-docs.form3.tech/api.html
common:
- type: PostmanWorkspace
  url: https://www.postman.com/kinlaneapi/form3/overview
- type: TrustCenter
  url: security/form3-trust-center.yml
- type: VulnerabilityDisclosure
  url: security/form3-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/form3-domain-security.yml
- type: AgenticAccess
  url: agentic-access/form3-agentic-access.yml
- type: OAuthScopes
  url: scopes/form3-scopes.yml
- type: Authentication
  url: authentication/form3-authentication.yml
- type: Security
  url: security/form3-vulnerability-disclosure.yml
- type: Compliance
  url: https://trust.form3.tech/
- type: SecurityTxt
  url: well-known/form3-security.txt
- type: WellKnown
  url: well-known/form3-well-known.yml
- type: Packages
  url: packages/form3-packages.yml
- type: SDKs
  url: packages/form3-packages.yml
- type: MCPServer
  url: mcp/form3-mcp.yml
- type: LLMsTxt
  url: llms/form3-llms.txt
- type: Overlay
  url: overlays/form3-payments-overlay.yaml
- type: Conformance
  url: conformance/form3-conformance.yml
- type: ErrorCatalog
  url: errors/form3-problem-types.yml
- type: Lifecycle
  url: lifecycle/form3-lifecycle.yml
- type: ChangeLog
  url: https://www.api-docs.form3.tech/changelog
- type: Conventions
  url: conventions/form3-conventions.yml
- type: Idempotency
  url: conventions/form3-conventions.yml
- type: DataModel
  url: data-model/form3-data-model.yml
- type: Webhooks
  url: asyncapi/form3-notifications-webhooks.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Website
  url: https://www.form3.tech/
- type: DeveloperPortal
  url: https://www.api-docs.form3.tech/
- type: Documentation
  url: https://www.api-docs.form3.tech/
- type: APIReference
  url: https://api-docs.form3.tech/api.html
- type: GettingStarted
  url: https://www.api-docs.form3.tech/api/tutorials/getting-started/introduction
- type: OpenAPI
  url: openapi/form3-payments.yml
- type: GitHubOrganization
  url: https://github.com/form3tech-oss
- type: Postman
  url: https://documenter.getpostman.com/view/5561717/TWDTNzaD
- type: StatusPage
  url: https://status.form3.tech/
- type: Blog
  url: https://www.form3.tech/news
- type: LinkedIn
  url: https://www.linkedin.com/company/form3
- type: TermsOfService
  url: https://www.form3.tech/legal/terms-and-conditions
- type: PrivacyPolicy
  url: https://www.form3.tech/legal/data-privacy-statement
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com