Sequence Check Control. In systems that use sequential master files (mostly legacy systems), the order of the transaction records in the batch is critical to correct and com-plete processing. As the batch moves through the process, it must be re-sorted in the order of the master file used in each run. An out-of-sequence supplier’s invoice record in a batch will prevent other downstream records from being processed. In more serious cases, the downstream records may be processed against the wrong suppliers’ accounts. A sequence check control needs to be in place to compare the sequence of each record in the batch with the previous record to ensure that proper sorting took place. Out-of-sequence records should be rejected and resubmitted, thus allowing the other records in the batch to be processed.