An internal check is the splitting of work tasks so that one person is not responsible for every step in a transaction. The splitting of tasks allows for the verification of work by a second person, thereby reducing the risk of fraud. An internal check also reduces the number of transactional errors, since the second person can spot and correct them as part of her ongoing work.
However, splitting tasks is less efficient, because there is a queue time involved whenever the transaction work flow shifts to a different person. Consequently, its use may be limited to high-value transactions where there is a greater risk of loss.