Aggregate Technical and Commercial Loss
It is unfortunate in that addition to T&D losses, there is also a loss in revenue because of non-realisation of billed demand which leaves a portion of the units billed as unrealised units. This commercial loss is further to the commercial losses up to the point of billing. The aggregate of T&D loss and loss since of non-realization of billed demand is termed as "AT&C loss" (Aggregate Technical and Commercial loss). The T&D losses have always been computed taking within account electricity bills issued to consumers as accrued income and not on actual collection. Therefore, T&D loss figures do not capture the major gap between the billing and the collection, except from the large amount of theft not captured in billing. The AT & C losses take this gap into account. Therefore, AT&C loss to the utility is the sum total of technical losses, commercial losses and loss due to non-realisation of total billed units. AT&C loss for a year is also expressed as percentage of Energy Input. It is the difference among units injected within the system and the units for that the payment is collected.
AT&C loss is a transparent measure of the whole efficiency of the distribution business as it measures technical as well as commercial losses. The schematic diagram display below captures the necessary elements of AT&C losses and is translated within terms of units both at the physical level of transmission and distribution and at the financial level of billing and collection.