It is very simple and easy process if you are worried about How to cancel money order that you had sent but has not yet been paid to the person to whom it was supposed to be delivered. The Indian Postal service has the facility to cancel the money order if the sender does not want to send it and wants the money back.
When the person fills in the form for sending the money order at the post time he is provided with the receipt, which is signed by the postmaster of that post office. If the person due to some reason want his money back and does not want the money order to be sent he can do so. For this the person has to apply at the same post office and provide the receipt that was given to him at first. For cancellation the postal services does not charge the person with extra surcharge.
If the money order has already been dispatched the payment can be stopped through telegram by the post office if you are willing to pay the charges for telegram. You can only cancel money order before it has been delivered at the address it was sent. But if the money order has already has already been deliver in that case you cannot cancel money order.