Invoice finalization makes certain properties on the invoice immutable (https://docs.stripe.com/invoicing/integration/workflow-transitions#post-finalized). According to the docs, invoice.customer_address, invoice.customer_email, etc. can't be changed after the invoice has been finalized.
In practice, this means if you...
- Make an invoice with a customer whose email is foo@test.com
- Finalize the invoice
- Change the customer email to bar@test.com
The customer's email on the finalized invoice is still foo@test.com.
This notebook demonstrates that changing customer details after invoice finalization doesn't impact the invoice.