As of release 4.0A you can set a rate manually for each date in a billing plan with partial billing. The amount billed is that converted from the local currency to the document currency at the rate you enter here.
A rate can also be entered at item level of the sales document (field Rate f. FI on tab page "billing document"). This fixed rate is then valid for all dates in the item billing plan for which no rate is specifically entered in the billing plan. If a rate is entered at both item level in field Rate f. FI as well as in the billing plan for each date, then the rate specified for each date is used during billing.
If no rate is entered at item level or at date level, then the conversion rate is determined when the invoice is created and forwarded to FI.
When using a header billing plan, all billing plans that are linked to this header billing plan are adjusted automatically. If, for example, you enter a rate manually for the first date, then this fixed rate is automatically copied to the corresponding dates in the billing plans of the items.