Customer

A customer is a person or a business the bank has identified. Accounts, counterparties and groups all refer to a customer by id.

Person or business

type is person or business. Both need legal_name, email, tax_id and address. A person also needs date_of_birth. A business may give formation_date. phone is optional and must be E.164.

tax_id is nine digits: an SSN or ITIN for a person, an EIN for a business. It is sealed when the customer is created and never returned. The object carries tax_id_last4 and tax_id_on_file instead.
address.country is an ISO 3166-1 alpha-2 code. A U.S. address needs a two-letter state and a five- or nine-digit postal_code.
PUT /customers/{id} changes the name, email, phone or address. It requires evidence and reason.

KYC state

A new customer has kyc_status pending and risk_rating unrated. POST /kyc-checks with the customer_id runs the provider check and a sanctions screening, stores a KYC check, and writes the decision to the customer: verified, rejected or review, with a rating of low, medium or high. A screening hit rejects the customer. A potential match turns a verified result into review.

A change of legal_name or address, a new record of a business's owners, or an approved tax id correction sends a verified customer back to review.

An account opens only for a customer whose status is active, whose kyc_status is verified, whose type matches the product and whose rating is not high. GET /customers/{id}/eligibility answers with the reasons when one fails.

The KYC provider is a simulator today. It verifies every customer with a low rating unless the legal name contains REJECT, REVIEW or HIGHRISK.

Relationships

An account lists its customers in owners. GET /accounts?customer_id= lists the accounts a customer owns.
A business records the people who own or control it as business parties: person customers, each with ownership_bps, exactly one marked control_person.
A customer group joins a parent business with its subsidiaries and affiliates. A customer belongs to one group at most. Members of an active group move money between each other as inter-entity transfers.

Every field is listed in the Customer object.