Customer ownership and omnibus custody

Define the customer relationship, beneficial ownership, nominee and omnibus custody model, books and records, reconciliation, transfers, and customer-facing disclosures.

Every production launch must answer three questions without ambiguity: whose customer is this, who legally holds the security, and which record proves the end investor's entitlement? The commercial agreement, customer terms, custody agreement, and API implementation must give the same answer.

Contract-first control

The API creates operational records; it does not create a legal trust, nominee appointment, or custody relationship by itself. Obtain jurisdiction-specific advice and execute the required broker, custodian, nominee, and customer agreements before accepting real money.

Operating model

End investor

beneficial owner

↓customer terms

Partner

customer experience + first-line support

↓externalId + subAccountId

MyStocks ledger

sub-account attribution

↓omnibus instruction

Broker / nominee

legal account holder where applicable

↓settled custody

Custodian / CSD

pooled market position

MyStocks maintains the sub-account ledger used to attribute pooled positions. The relevant regulated broker, custodian, nominee, or CSD holds the market-level position under the arrangement approved for that jurisdiction. A portfolio response is therefore an operational entitlement record, not a claim that the end investor has an individually named CSD account.

Responsibility matrix

Control	Partner	MyStocks	Broker / custodian
Customer contract and consent	Own and retain	Provide required platform disclosures	Supply market-specific terms
Customer identity and authority	Verify	Enforce KYC state received through the API	Perform any required reliance review
Beneficial-owner attribution	Supply stable `externalId`	Maintain `subAccountId`, holdings, tax lots, and audit history	Reconcile pooled position
Order instruction evidence	Capture intent and disclosures	Persist request, idempotency key, quote, and execution state	Retain venue execution record
Asset servicing	Notify customer and collect elections	Allocate events to sub-accounts	Receive and process issuer/CSD event
Books-and-records requests	Coordinate customer response	Export platform ledger and event evidence	Provide custody and execution statements

Minimum customer record

Keep one durable customer record that connects your identity system to the MyStocks ledger:

Field	Control purpose
`externalId` and `subAccountId`	Stable cross-system identity; never recycle identifiers
Legal name, date of birth/incorporation, jurisdiction	Customer and regulatory classification
Beneficial owners and controllers	Natural persons who ultimately own or control a legal customer
Account authority	Persons permitted to place orders or change instructions
Terms and disclosure versions	Evidence of what the customer accepted and when
Broker/custody market mapping	Executing and custody chain applicable to the account
Restrictions and legal holds	Freeze, deceased estate, court order, sanctions, or dispute status

Do not store passport images, biometrics, or unnecessary source documents in free-text API fields. Keep sensitive evidence in the approved KYC system and send only the structured assertion required by POST /users/{id}/kyc.

Daily books-and-records control

Reconcile each security's pooled broker/custodian units to the sum of attributed sub-account units.
Reconcile cash, unsettled trades, dividends, fees, and corporate-action allocations.
Classify differences as timing, mapping, external statement, or ledger exceptions.
Prevent silent balancing entries; require an identified owner, evidence, and approval.
Escalate unresolved unit or cash differences before the next trading session.

Use GET /report/reconciliation for the platform view and compare it with the dated broker/CSD statement. The Custody and beneficial ownership page describes the evidence required for GA.

Customer-facing disclosure checklist

Identify the contracting entity and the entity providing regulated brokerage or custody.
Explain whether securities are held in an omnibus, nominee, or individually named account.
State how beneficial ownership is recorded and how customers receive statements and confirmations.
Separate execution from legal settlement and explain when cash or securities become withdrawable.
Explain the treatment of fractional entitlements, voting rights, dividends, taxes, fees, and FX.
Describe transfer-out, account closure, death, incapacity, attachment, and insolvency procedures.
Disclose applicable investor-compensation or protection arrangements without implying universal coverage.

Evidence required before production

Evidence	Owner	Release condition
Executed custody/nominee agreement per market	MyStocks + broker/custodian	Names the account structure and asset-protection treatment
Approved customer terms	Partner legal	Matches the operational model and market disclosures
Ledger-to-custody reconciliation	Operations	`BALANCED`, with external statement date recorded
Transfer and insolvency playbook	Joint operations	Tested contacts, data export, and authority matrix
Sample statement and trade confirmation	Partner	Shows beneficial owner, instrument, fees, FX, and settlement state