Yes, as long as you act before the order goes into production. What you do depends on whether you have paid for it yet.
Before you pay: edit it yourself
While an order is still in the Needs payment state, you can edit the customer's shipping address yourself. Do it before you click Fulfill and pay. Nothing has been sent to the warehouse yet, so the change is straightforward and there is no need to contact us.
After you have paid: message us straight away
Once the order is paid it moves into our processing workflow, so a change is no longer guaranteed. Contact support in chat as soon as you can with the new address and we will try to update it for you, but not guaranteed.
The cutoff is not shipped versus not shipped. It is whether the order has entered production or packing. Before that, we can usually help. After that, changes cannot be made.
To give yourself the best chance, include:
Which order needs the change
The full corrected address, exactly as it should appear on the label
Build the check into your routine
If address accuracy matters to you, leave auto-fulfillment switched off. Every order then pauses for your review, which gives you a chance to catch a bad address while it is still free to fix.