After a CDCI contracts negotiation is confirmed (entries marked in red), it can no longer be cancelled if bills generated for this routine have already been written-off.
If these canceling should be performed, procedures for bills write-off in Accounts Receivable and Accounts Payable must be cancelled, as it was mentioned.
See Also
For further information on Cancelling of Write-off, check Accounts Receivable and Accounts Payable.