Check whether a customer name is unique

When to use this endpoint

Use Customer_checkNameIsUnique when creating a customer through a workflow that follows the tenant duplicate-name policy.

It is not suitable for an unchanged edit because it has no customer ID to exclude. Customer_createData invokes it only when customer-name-allow-duplicate is disabled.

Authentication and permissions

The request must authenticate with signed API-key fields or a logged-in CRM session. The handler performs no additional page or role-permission check.

The lookup and any write use the authenticated tenant; an ID from another tenant cannot be addressed through this call.

Parameters

Parameter	Type	Required	Description
`name`	String	Yes	Proposed name. It is trimmed and lowercased before an exact database comparison. A present blank string is accepted.

Example request

$result = FM_api('Customer_checkNameIsUnique', [
	'name' => 'Northwind Service Centre',
]);

Example response

{
  "warning": "Customer Name must be unique",
  "countID": 2
}

A name with no matches returns {"ok":1}. countID is the number of matching non-deleted rows, not a customer ID.

Errors and unusual responses

Response	Condition
`{"error":"not logged in"}`	No authenticated tenant context is available. Invalid signed credentials can be rejected by the dispatcher before the handler runs.
`{"error":"missing or invalid parameter: name"}`	`name` is omitted.

Legacy application errors may be returned with HTTP 200. Check the decoded response for error, not only the HTTP status.

Behaviour and edge cases

Soft-deleted customers are excluded; inactive customers are included.
The endpoint does not read customer-name-allow-duplicate; the caller decides whether a warning matters.
There is no exclusion ID, result list, filtering, or pagination.

See it in Fieldmotion

CRM1

No direct production CRM1 JavaScript caller was found. The layout-driven Customer_createData server path calls this check when duplicate names are disabled.

CRM2

CRM2 customer creation uses Customer_createData, which calls this endpoint internally under the tenant duplicate-name setting; there is no direct browser request to filter for this function.

Related endpoints

Customer_new has its own duplicate-name suffix behavior.
Customers_list can return the actual matching records when IDs are needed.