This topic assumes that you have decided to use the first or third scenario described in Master data: Overview.
Using Manager, select > . The dialog is displayed.
Select to use master data to identify suppliers. This also connects the master data to Verify, so you can use the supplier registry when searching for suppliers in the dialog.
Recommended: Select the second setting in the dialog. This locks the suppliers list in Verify so you can only choose suppliers from the supplier registry. In other words, if this setting is selected, you cannot type in new suppliers while verifying. However, invoices from new or one-time suppliers can still be handled. (How?)
Click to close the dialog and use this policy until it is changed.