> ## Documentation Index
> Fetch the complete documentation index at: https://www.plain.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# upsertAccountField

> Sets or updates a field value for a specific account. Identify the target field using `accountFieldIdentifier` (account ID + external field ID) and pass exactly one value argument matching the schema's `type` (e.g. `stringValue`, `numberValue`, `booleanValue`, `arrayValue`, `dateValue`, `userReferenceValues`, or `accountReferenceValues`). Requires the `tenantField:create`, `tenantField:update`, and `tenantFieldSchema:read` permissions. Identifying the account by `externalId` also requires the `tenant:read` permission.



This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.