Bill Purchase Order > Rate Used When Item Rate on the Vendor Bill is not Sourced from the Purchase Order Rate

Check the Accounting Preference Use Purchase Order Rate on Bills box if a user prefers to use the Purchase Order rate on Vendor Bills instead of using the Item Receipt rate.

However, if under Setup > Accounting > Accounting Preferences > Order Management > Receiving section > Use Purchase Order Rate on Bills = False and no Item Receipt is associated with the Purchase Order yet, the Rate that will be used on the Vendor Bill created from the Purchase Order is the highest amount used in transactions associated to the Purchase Order before the Vendor Bill was created.