An amended return is a standalone return on its own. When you start the process of amending a tax return previously filed, the refund/balance due meter zeroes out.
If you are seeing a zero balance on an amended return after you have made changes to your originally filed return, then that means that the changes you made did not affect the bottom line of your original return. You will not receive an additional refund and you do not owe any taxes.
Depending on the change that you made, you may still need to file the amended return even though there is not a change in the refund/balance due.
Take a look at the information below for guidance on when you would need to file the amended return.