Unfortunately, you cannot amend your transaction once it has been set up. For instant Payment, you cannot cancel your transaction once confirmed. For future dated payments, should you wish to cancel the transaction, please log in to your Citi Mobile App. You can review and cancel your existing payment instructions by selecting the Citi PayAll option under "Payments" tab. Please note that you may only cancel a transaction no less than 3 Business days before the payment due date.