Hi famouscarpentry,
Being able to update your address on your account is a great way to make sure your account information is correct. I can help go over this with you.
Updating your information in QuickBooks Online is a quick process to help you save time. In order to update your address in QuickBooks Online you'll need to go to Gear>Accounts and Settings>Company. From there click the pencil icon on the right hand side of company address to edit the address shown and then click save. If the old address still shows I recommend checking your invoice template incase it was manually entered on the invoice itself. You can edit your template by following the steps in this article. It can also be showing the wrong address due to your browser pulling up old information from your cache and cookies. In order to fix this you can follow the steps located here.
Hope this helps!