Vista provides you with the flexibility to allow/disallow duplicate AP reference numbers when entering AP transactions (AP Transaction Entry, AP Unapproved Invoice Entry).

1. In the AP Company Parameters form, select the Prevent duplicate AP Reference check box on the Invoice Options tab.
2. Choose a default validation method to use for checking reference numbers. If you wish to override the default option for a vendor, you can do so in the AP Vendors form.

   The following describes how the validation methods function:

   • 0-No Override - This option is only available in the AP Vendors form and indicates that an override is not used for the currently selected vendor. In this case, the option specified at the company level is used.

   • 1-By Vendor & Co - Use this option to have the system check for duplicate reference numbers by vendor within the current company. If selected, and the validation process encounters a duplicate reference number for the specified vendor in the current company, a warning displays.

   • 2-By Vendor X-Co - Use this option if you have several companies that share the same vendor file and you want the validation process to check all companies for duplicate reference numbers. If selected, and a duplicate reference number is encountered for the vendor in any of the companies sharing the vendor file, a warning is displayed.

   • 3-By Master Vendor & Co - Use this option if you are using the master vendor/sub vendor feature, and you want the validation process to include all associated vendors within the current company when checking for duplicate reference numbers. If selected, and the system encounters a duplicate reference number for the master/sub vendor group (i.e. the master vendor and all assigned sub vendors) in the current company, a warning is displayed.

   • 4-By Master Vendor X-Co - Use this option if you are using the master vendor/sub vendor feature and you have several companies sharing the same vendor file that should be included when checking for duplicate reference numbers. If selected, and the system encounters a duplicate reference number for the master/sub vendor group (i.e. the master vendor and all assigned sub vendors) in any of the companies sharing the vendor file, a warning is displayed.

   In all cases, invoice entry is only allowed if the Prevent duplicate AP Reference check box is not selected. Duplicate AP references are defined in part by the Enable Case-Insensitivity on AP References check box. See this check box's F1 field help for further information.

   Note: If you plan to use the 'master vendor/company' or 'master vendor/cross-company' methods, and you only have a few vendors set up using the 'master vendor/sub vendor' theme, it is suggested that you set these levels at the vendor level, and set the company level to either 1 or 2 (i.e. if you set the vendor level to 3, set the company level to 1). This way, the master vendor/sub vendor validation only occurs for those vendors designated as master vendors or sub vendors.