Onboarding requirement matrix

API onboarding is documentation-led. An API merchant can build a correct integration from this guide without calling POST /v2/validation-rules/senders/resolve. That resolver is used by Mesta's portals and is not a required public integration step.

The requirements below are added to the normal fields and documents required by POST /v2/senders, POST /v2/senders/ubo, and the sender's country. When multiple capabilities are selected, apply the union of their requirements. Supply a shared sender or person field only once.

Capability summary

Capability	Additional information supplied by the merchant	Supplied or derived by Mesta
`eur_account`	Business website, Directors' and shareholders' registry, at least one Director or Authorized Representative, and nationality for every UBO and qualifying representative	Industry code and trading address
`usd_account`	Business tax ID and a tax identifier for every UBO	None
`gbp_account`	No capability-specific fields beyond normal sender onboarding	Account setup
`mxn_account`	No capability-specific fields beyond normal sender onboarding	Account setup

The eur_account and usd_account capabilities also depend on normal business-onboarding values such as the legal name, incorporation date, business type, registered address, UBO birth date, and UBO ownership percentage. These values already exist in their normal sender or UBO request bodies and must not be duplicated under capability-specific objects.

Sender fields

Required when	Public field	Meaning	Create	Update after creation
All business senders	`identificationNumber`	Business or company registration number	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`usd_account`	`taxIdentificationNumber`	Business tax ID, such as an EIN	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`eur_account`	`websiteUrl`	Business website; a website-absence reason does not satisfy this capability	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`eur_account` or `usd_account`	`registrationDate`	Incorporation date	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`eur_account` or `usd_account`	`fullName`	Legal business name	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`eur_account` or `usd_account`	`businessType`	Legal business type	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`eur_account` or `usd_account`	`addresses`	Registered business address	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`
`eur_account`	`phone`	Business phone number	`POST /v2/senders`	`PATCH /v1/senders/{senderId}`

identificationNumber and taxIdentificationNumber are different public fields. Do not send a business tax ID in identificationNumber when usd_account requires taxIdentificationNumber.

UBO fields

Create each UBO with POST /v2/senders/ubo. Update a persisted UBO with PATCH /v1/senders/ubo/{uboId}.

Required when	UBO condition	Public field	Notes
Normal onboarding	Every UBO	`firstName`, `lastName`, `email`, `phone`, `birthDate`, `ownershipPercent`, `address`, `identity`, `pepDeclaration`	Normal UBO identity and ownership information
`eur_account`	Every UBO	`nationality`	ISO 3166-1 alpha-2 country code; nationality is distinct from residence and identity-document country
`usd_account`	UBO outside the United States	`identificationNumber`	The person's tax identification number
`usd_account`	UBO in the United States	`identity.documentType: "SSN9"` and `identity.documentNumber`	An SSN9 identity satisfies the UBO tax-ID requirement; do not ask for the same datum again in `identificationNumber`

Identity-document front and back images remain conditional on the selected document type and country. Follow Supported identity document types; do not assume that every document type requires both sides.

Directors and Authorized Representatives

eur_account requires at least one associate whose roles contains director or authorized_representative.

Create an associate with POST /v1/senders/associates.
Update an associate with PATCH /v1/senders/associates/{associateId}.
If the representative is already a UBO, send linkedUboId. Mesta reuses the person's stored data rather than collecting it twice.
An unlinked representative supplies their personal, address, identity, birthDate, and nationality values directly.

The onboarding verification response identifies the specific associate or missing role when more information is required.

Documents

Upload sender documents with POST /v1/senders/{senderId}/documents.

Required when	Document type	Notes
Country and entity rules require it	`business_registration_proof`	Proof of business registration
Country and entity rules require it	`address_proof`	Proof of the business address; may also be used for trading-address extraction
Sender is a financial institution	`fi_registration_proof`	Financial-institution registration evidence
`eur_account`	`directors_registry`	Directors' and shareholders' registry; multiple files are supported

UBO and unlinked-representative identity documents are supplied in the corresponding person's identity flow. The required front/back files depend on country and document type.

Values Mesta derives automatically

API merchants supply only the documented sender, person, and document fields.

Capability	Value	Behaviour
`eur_account`	Industry code	Mesta derives it from the sender's business information
`eur_account`	Trading address	Mesta attempts to extract it from the submitted documents; if operations or merchant action is later required, the setup-request response returns an actionable blocker

Automatically collected values do not block the initial call to POST /v1/senders/{senderId}/verify merely because extraction has not completed.

Multiple-capability example

For capabilities: ["eur_account", "usd_account"], submit the normal sender and UBO data once, then add:

taxIdentificationNumber for the business;
websiteUrl and the directors_registry document;
at least one Director or Authorized Representative;
nationality for every UBO and qualifying representative; and
identificationNumber for each non-US UBO, or SSN9 identity data for each US UBO.

The shared legal name, incorporation date, registered address, business type, UBO birth date, and ownership percentage are not repeated. Verification evaluates the complete union and returns actionable onboarding endpoints for anything still missing.