Which transaction code is used for posting a vendor invoice in SAP FI?

The transaction code used for posting a vendor invoice in SAP FI is FB60. This transaction code specifically accommodates the entry of invoices from vendors without reference to a purchase order. When a user inputs FB60 in the command field, it opens the Invoice Document screen, allowing for the detailed entry of the necessary information such as the vendor number, invoice date, amount, and any relevant taxation details.

While MIRO is used to post invoices related to purchase orders, it is not exclusively for general vendor invoices. Instead, MIRO typically references a material movement or a service rendered associated with a purchase order.

Other transaction codes such as F-02 are used for general posting and could be used for a variety of document types but are not specific to vendor invoices. FK10N is, on the other hand, used for displaying vendor balances and account information, rather than posting invoices.

In summary, FB60 is specifically designed for posting vendor invoices directly, making it the most appropriate answer for this question regarding vendor invoice transactions in SAP FI.