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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Form3 the way a machine reads it — 37 machine-readable artifacts across 1 API, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Form3 scores 45.1/100 (developing), with a separate agent-readiness read of 36/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
Put this on your own site. The badge is drawn live from Form3's current Kin Score — paste it once and it updates itself every time the score is recomputed. It follows your visitor's light or dark setting, and it links back here so anyone who sees it can read the full breakdown.
<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/form3/"
title="Form3 on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/form3.svg"
alt="Form3 Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/form3/)<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/form3/"
title="Form3 on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/form3/card.svg"
alt="Form3 Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile Form3
Each block below is one kind of artifact we hold for Form3. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 28
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
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 within the panel for all 28 ·
Postman Collections 1
A runnable collection turns the contract into something a developer can execute in seconds. We profile them because the fastest way to trust an API is to make a real call against it.
Ready-to-run Postman collections for exercising this provider's APIs.
Form3 Public API
POSTMANOpen Collections 1
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Form3 Public API
OPEN COLLECTIONEvent Specifications 1
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
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 — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for Form3 — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
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
Scroll within the panel for all 7 ·
Build 5
SDKs, sample code, and the tooling you integrate with
Access & Security 8
Authentication, authorization, and security posture
Scroll within the panel 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
← All providers · Data indexed from github.com/api-evangelist/form3 · machine-readable index on apis.io
This is an independent, third-party profile of Form3, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
info@apievangelist.com
·
Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and
you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.