When ending a customer relationship, you can cascade the end date to all inventories.
Use PATCH /customers with the endDate property and pass the optional header parameter cascade_end_date to automatically end-date all associated inventories.
Example:
PATCH /customers/123
Headers: cascade_end_date: true
{
"op": "replace",
"path": "/endDate",
"value": "2026-12-31"
}