We need to update (not import) 8000 customer records in Square with Reference IDs from an external system. The import tool in the UI does not appear to support updates, only inserts, and the API only seems to allow updating a single customer record in each call.
Is there any way to do this? Or do we have to attempt 8000 API calls, which I imagine would likely cause an internal API error?
Thank you
Currently there isn’t a bulk endpoint that you can use to update large batches of customer records. You will need to update each customer record individually. When updating large amounts of records you could hit rate limits so we encourage you to handle the limit gracefully by building a retry mechanism. This mechanism should have an exponential backoff schedule to reduce requests when volume is necessary. Also some randomness wouldn’t hurt to avoid a thundering herd effect. 
@Bryan-Square Ok, and is there no way to use the Import feature in the UI to update records, instead of create new records?