# CustomerBankAccountUsage

## Description

Links a reusable PartnerBankAccount to a CustomerAccount for RECEIPT or REFUND processing.

## Domain Model Definitions

### Model type

Standard

### Command Definitions

- [createCustomerAccount](../command/CreateCustomerAccount.md) - Creates initial bank usages

### Query Definitions

- [GetCustomerAccount](../query/GetCustomerAccount.md) - Retrieves the owning account

### Models

- CustomerBankAccountUsage

### Invariants

- Account and bank account must belong to the same BusinessPartner
- The account, bank account, and purpose combination is unique
- At most one default exists for each account and purpose

### Relationships

- **References CustomerAccount**: Customer transaction context
- **References PartnerBankAccount**: Reusable partner-owned bank account