Use this endpoint to create or update company records, using a unique attribute to search for existing companies (for example, the domains attribute). If a company is found with the same value for the matching attribute, that company will be updated. If no company with the same value for the matching attribute is found, a new company will be created instead. If you would like to avoid matching, please use the Create company endpoint.
If the matching attribute is a multiselect attribute, new values will be added and existing values will not be deleted. For any other multiselect attribute, all values will be either created or deleted as necessary to match the list of supplied values.