# Account Creation & Hierarchical Structure

Corporate Clients onboarded to **VAS** use a **hierarchical account model**. This model provides clear segregation of funds, supports regulatory compliance, and enables fine-grained tracking of all Customer transactions.

At the highest level, each Corporate Client has:

- **Parent Accounts** (per currency)
- **Sub Accounts** (per Customer, under a Parent)
- **Settlement Account** (for all external inflows/outflows)
- **Operational Account** (separate, non-VAS, for the client’s own day-to-day operations)


## Sub Account

A **Sub Account** is the core ledger used to segregate Customer funds from the Corporate Client’s operational balances.

- Always linked to a **Parent Account**.
- Acts as a **virtual, non-interest-bearing account**.
- **No direct relationship with BCB** — it is governed by agreements between the Corporate Client and their Customers.
- Restrictions:
  - ❌ No debit/credit cards
  - ❌ No cheque books
  - ❌ No account statements
- No minimum or maximum balance requirements.


**Use case:** Corporate Clients can open one Sub Account per Customer, ensuring each Customer’s balances are isolated.

## Parent Account

The **Parent Account** acts as the **main ledger** for a group of Sub Accounts.

- Tracks all Customer transactions, balances, and fund movements.
- Corporate Clients may have **multiple Parent Accounts**:
  - One per currency.
  - Each may contain multiple Sub Accounts.
- Provides a **consolidated view** across all linked Sub Accounts.
- Created for both new and existing Corporate Clients.
- Balance remains at **zero**:
  - All credits/debits are immediately swept to/from the **Settlement Account**.


**Use case:** Developers integrating with reporting APIs will typically use the Parent Account for **roll-up views** across Customers.

## Settlement Account

Every VAS Corporate Client must have a **Settlement Account**.

- Used **exclusively** for inbound and outbound transactions with **external counterparties**.
- Transfers between **Settlement** and **Sub Accounts** are only possible via the **Parent Account**.
  - ✅ Ensures reconciliation and audit integrity.
  - ❌ Direct transfers between Sub ↔ Settlement are not allowed.
- Only the **Corporate Client** can initiate transfers.


**Use case:** Developers building payments integrations must always route external flows via the **Settlement ↔ Parent ↔ Sub** path.

## Operational Account

The **Operational Account** is **not part of VAS**. It represents the Corporate Client’s day-to-day banking account with BCB.

- **Existing Clients**: Already have an Operational Account.
- **New Clients**: Open one through standard BCB onboarding.
- This account is **not linked to VAS flows**.
- It does **not reflect VAS balances or transactions**.


**Use case:** Developers should not expect to see VAS-related balances in Operational Account APIs. Treat this account as **out of scope** for VAS workflows.

## Developer Notes

- APIs that expose balances or transactions will clearly differentiate between **Operational**, **Parent**, **Sub**, and **Settlement** accounts.
- **Identifiers**:
  - Parent and Settlement Accounts have a direct relationship with BCB systems.
  - Sub Accounts exist virtually (ledger-only) but are still addressable in API workflows.
- **Transfers**:
  - Always enforce the **Settlement → Parent → Sub** routing in client logic.
  - Attempts to bypass this structure will return validation errors.
- **Reporting**:
  - Parent Accounts = roll-up view.
  - Sub Accounts = granular, per-Customer view.