Because these exps are paid/payable to persons. person includes Sole Proprietor, Partnership Firms, HUF, Co; etc.Personal accounts always appear in B/S until it is transfered to expenditure by debiting to P&L A/C.
There is no specific abbreviation for the term WIRE because when the payment is being made using this option, you will not see the physical movement of funds. It is all electronic. It is just like a current passes through Wire.
Therefore Electronic movement of funds is campared with WIRE.