A billing process is disclosed for a information dispersal system or digital data storage system. In one embodiment of the invention, the original data to be stored is separated into a number of data "slices" or shares in such a manner that the data in each subset is less usable or less recognizable or completely unusable or completely unrecognizable by itself except when combined with some or all of the other data subsets. These data subsets are stored on separate digital data storage devices as a way of increasing privacy and security. As dispersed file shares are being stored or removed from a grid of distributed storage locations, a set of metadata tables are created, separate from the dispersed file share storage, to maintain information about the original data size of each block, file or set of file shares dispersed on the grid. The original data size information in these separate metadata tables is used to determine usage information based upon the original file size even though the file has been dispersed onto a storage grid that contains file slices who size may not relate to the original file size and the file slices may have been compressed by the system in order to reduce storage space or improve transmission time. As such, the billing process is able to enable a broad range of commercial billing options for billing for commercial data services on an information dispersal grid.