At the end of the week there will be a number of similar documents relating to customer payments. These will be put into a batch and a cover slip attached. A clerk will obtain a batch number which will be unique to this batch and the batch number will be entered in the department's batch register. The clerk will calculate and write on the batch slip two or more batch totals. These are the total number of documents in the batch and the totals of any important fields. In the case of invoice payments the second batch total will be the total of all the individual payments in the batch.

The data is then sent to the computer department for data preparation. The batch totals will also be prepared for input. When the data is input the computer will calculate the batch control totals from the input. Finally the newly calculated values will be compared with the values calculated by the clerk. The process of comparison between the two sets of values is called reconciliation. If the control totals do not reconcile then there must have been an error. This could be due to a missing document, an error in data preparation or an error in the original calculation of the control totals. The source of the error will be traced and appropriate action taken.