Create many accounts and their first locations at once from a CSV file, one account and one location per row, up to about 100,000 rows. Returns an import_id immediately; the import runs in the background, so poll Check import status. Rows with problems are skipped and reported, the rest go through, and re-running the same file skips rows already imported. The CSV columns are listed on the guide page.

Prerequisites: a CSV file (max 100 MB) whose header row has every required column, and plan_id values set up for your partner.

Authentication: Partner token. The import runs for your partner; any other token gets 403.

Rate limit: none.