# CustomerAddressUsage

## Description

Links a reusable PartnerAddress to a CustomerAccount for a BILL_TO or SHIP_TO purpose. Defaults are account- and purpose-specific.

## Domain Model Definitions

### Model type

Standard

### Command Definitions

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

### Query Definitions

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

### Models

- CustomerAddressUsage

### Invariants

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

### Relationships

- **References CustomerAccount**: Customer transaction context
- **References PartnerAddress**: Reusable partner-owned address