An online data entry program is used for original entry of vendor invoices. A batch check-writing program occasionally prepares a check for a vendor not yet included in the vendor file. Checks for such vendors contain nonsense characters in the payee field. The most effective programmed control to prevent this kind of error is to perform

1. A record lookup for vendors during data entry.
2. A verification of vendors in the check-writing program.
3. A completeness test on fields in the check-writing program.
4. A batch control total check on vendor payments.