No, it will not deduct payments or money automatically from a user’s account. It is clearly mentioned in NPCI’s frequently asked questions that the system will never auto deduct payments from an account.
Each transaction has to be manually verified by the user by entering the UPI PIN to authorize the payment. Without UPI PIN transactions cannot proceed, therefore there is practically no chance of money getting deducted from a user’s account.
So in case you notice money deducted from your account, you should check transaction history in bhim app’s interface. You can also enquire about unrecognized transactions with your bank to get more details.