Canceling an invoice means you can totally remove the invoice from the system, only it will give a record history on the job that the invoice was labeled as canceled.

2. Cancel or Delete Invoice in Odoo 13
Canceling an invoice means you can totally remove the invoice from the system,
only it will give a record history on the job that the invoice was labeled as
canceled.
At the same time, you can cancel an invoice the time and cost will be available to
invoice again. Whenever the invoice has been confirmed and is awaiting
payment, it can be canceled.
Odoo 12 has its own personal module like the account cancel module to
cancel the invoice. In Odoo 13 the functionality of the account cancel module is
merged to the main accounting module and removed the module of the account
cancel module.
The invoice should never be deleted. Whenever a condition occurs that needs
the invoice to be canceled or changed, arising a credit note is normally enough.
A credit note enables you to cancel an invoice accurately, and correctly.
Whenever the invoice has already been sent, an updated document is no longer
enough. At that time, you will need to continue in two steps:

3. Firstly: You can cancel the old invoice and issue a new one. Now you can
cancel the original invoice via creating a cancellation invoice with a negative
invoice amount.
At that time, the original invoice is no longer valid and is canceled at the same
time, the cancellation invoice is posted.
Now you can check the important point like the cancellation invoice has its
particular invoice number.
Secondly: Now you will require to create a new invoice, with a new invoice
number.
Now Lets' see how to cancel or delete the invoice in
Odoo 13
First of all, you can install the Accounting module in your database.
Now you can create the sample invoice in the accounting module.

4. Go to Accounting module -> Customers -> Invoice -> and click on the
create invoice. At that time, post it and send it to the customer.

5. Therefore the invoice is in posted status. Whenever you want to move the
posted invoice back to the drafted stage via clicking on the Reset To Draft
button.
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6. Whenever you want to cancel the invoice, now you can click on the cancel entry
button. Therefore the invoice is canceled before approving. At that time, your
invoice is going to the draft stage.

7. After clicking on the cancel entry button, now you can click on the "Reset to
draft" button to change the invoice back to the draft stage to another stage
like the Cancel entry stage.

8. Now you can click on the Cancel Entry button then your invoice is successfully
canceled.

9. After clicking on the cancel entry button now your invoice status is changed
like canceled stage. At that time, you can view the Cancelled status on the top
right corner.

10. Whenever the invoice has any ongoing payment, now you can do the Un-
reconcile them before canceling.
At that time, you can choose the journal entries and un-reconcile them first.
Later you will receive a notification to unreconciled entries.