Before you can use the automatic invoice rounding function, you must set up rounding rules.
To set up rounding rules for local currency
In the Search box, enter General Ledger Setup, and then choose the related link.
In the General Ledger Setup window, on the Application FastTab, fill in the Amount Rounding Precision, Unit-Amount Rounding Precision, Inv. Rounding Precision (LCY) and Invoice Rounding Type (LCY) fields. For more information about a specific field, select the field, and then press F1.