You can change your mailing address in your Brand settings. This is the address that appears at the bottom of your invoices.
Updating your brand address doesn't necessarily update it in places that you have manually added your mailing address. For instance, you may also want to double check that the old address is not included in any automatic invoice reminders or custom payment details (both located under Settings > Invoices & Payments > Invoice Settings). You should also double-check your email signature (Settings > Emails > Signatures) and anywhere else that you may have added the address manually.