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 28 APIs on the APIs.io network, including Account Identification API, Accounts API, Account Validation API, and 25 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 33 more developer resources.
Kin Score
APIs 28
Individual APIs this provider publishes, each with its own machine-readable definition.
Form3 Account Identification API
The AccountIdentification API from Form3 — 2 operation(s) for accountidentification.
Form3 Accounts API
The Accounts API from Form3 — 3 operation(s) for accounts.
Form3 Account Validation API
The AccountValidation API from Form3 — 2 operation(s) for accountvalidation.
Form3 ACE API
The ACE API from Form3 — 2 operation(s) for ace.
Form3 Audit API
The Audit API from Form3 — 2 operation(s) for audit.
Form3 Branches API
The Branches API from Form3 — 2 operation(s) for branches.
Form3 Branch Identification API
The BranchIdentification API from Form3 — 2 operation(s) for branchidentification.
Form3 Claims API
The Claims API from Form3 — 8 operation(s) for claims.
Form3 Direct Debits API
The DirectDebits API from Form3 — 26 operation(s) for directdebits.
Form3 Direct Debits Reads API
The DirectDebitsReads API from Form3 — 1 operation(s) for directdebitsreads.
Form3 Mandates API
The Mandates API from Form3 — 9 operation(s) for mandates.
Form3 Metrics API
The Metrics API API from Form3 — 3 operation(s) for metrics api.
Form3 Name Verification API
The Name Verification API API from Form3 — 3 operation(s) for name verification api.
Form3 Oauth2 API
The Oauth2 API from Form3 — 1 operation(s) for oauth2.
Form3 Organisations API
The Organisations API from Form3 — 2 operation(s) for organisations.
Form3 Payment Reads API
The PaymentReads API from Form3 — 31 operation(s) for paymentreads.
Form3 Payment Writes API
The PaymentWrites API from Form3 — 18 operation(s) for paymentwrites.
Form3 Platformsecurityapi API
The platformsecurityapi API from Form3 — 2 operation(s) for platformsecurityapi.
Form3 Public Keys API
The Public Keys API from Form3 — 4 operation(s) for public keys.
Form3 Qualified Transactions API
The QualifiedTransactions API from Form3 — 2 operation(s) for qualifiedtransactions.
Form3 Query API
The query_api API from Form3 — 10 operation(s) for query_api.
Form3 Reports API
The Reports API from Form3 — 4 operation(s) for reports.
Form3 Roles API
The Roles API from Form3 — 2 operation(s) for roles.
Form3 Scheme File API
The Scheme File API API from Form3 — 6 operation(s) for scheme file api.
Form3 Scheme Messages API
The SchemeMessages API from Form3 — 3 operation(s) for schememessages.
Form3 Subscriptions API
The Subscriptions API from Form3 — 2 operation(s) for subscriptions.
Form3 Transaction File API
The Transaction File API API from Form3 — 7 operation(s) for transaction file api.
Form3 Users API
The Users API from Form3 — 11 operation(s) for users.
Scroll for all 28
Postman Collections 1
Ready-to-run Postman collections for exercising this provider's APIs.
Form3 Public API
POSTMANOpen Collections 1
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Form3 Public API
OPEN COLLECTIONEvent Specifications 1
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Form3 Notifications Webhooks
ASYNCAPISecurity Posture 4
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
Recommended x-agentic-access execution contracts for AI agents.
Resources
Get Started 2
Portal, sign-up, and the first successful call
Documentation 3
Reference material describing how the API behaves
Agent Surfaces 5
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 7
Pagination, idempotency, versioning, errors, and events
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Build 5
SDKs, sample code, and the tooling you integrate with
Access & Security 8
Authentication, authorization, and security posture
Scroll for all 8
Operate 2
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 2
Properties that don't map to a standard resource type
Source (apis.yml)
Work with this as data
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