In SAP FI, you can post a vendor invoice in foreign currency so you can do currency analysis. If you post in FI, you can directly post backdate invoices.
Use the T-code F-43 or go to Accounting → Financial Accounting → Accounts Payable → Document entry → Other → Invoice → General.
In the next window, enter the following details −
Press Enter and a new window will open. Input the amount, calculate tax, Tax code, PstKey, Account (Revenue account) and press Enter.
The amount in local currency is displayed in the field. Click the Save button at the top and note the document number.