On the Payment Details tab, you can provide information about documents associated with this bank payment. 
The "Bank Payment (create)" form. The Payment Details tab in Single-Row mode
In the Employee Expense Report field, select an employee expense report listing the expenses which are reimbursed by this payment.
There is a switch for changing the display mode which is located to the right on the tab, Table Mode. Use Table mode if you need to apply the payment amount to multiple planning documents or projects. You can add documents one by one to the list in the table. 
The "Bank Payment (create)" form. The Payment Details tab in table mode
If the Project Costing functionality is enabled in the application on the Administration > Settings > General Settings form, you can link a bank payment with a related project which you can select in the Project field (to find a project, start typing its name or code in the field).
The Planning Document field is available if the Use a payment calendar option is selected on the Administration > Settings > Cash Management form. The field is auto- populated in case when the payment is based on a Money Transfer (Plan) or Money Payment (Plan) document.
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