Hi gsb06.

Currently, the feature to update multiple customers' info all at once is unavailable in QBO.

Though, you can follow the steps given by my colleague, Kristine Mae, in changing the customer's info manually one at a time.

In the meantime, I'd like you to visit our blog site to stay current with our products and feature updates in QBO.

You can always place a comment here if you have more questions. I'll be right there to help. Take care!