Prerequisites for Using Payment Directives 
In order to use Payment Directives, you must carry out Customizing in the Implementation Guide for Financial Accounting as well as for Funds Management in the Public Sector.
There are two sets of activities that you must carry out in order to use Payment Directives.
The IMG activities for payment directives themselves.
Settings or data referring to SAP Financial Accounting.
These are explained in further detail below.

The payment directive and the invoice for which this payment directive was created must belong to the same fiscal year. Otherwise no update is possible in FM tables.
In order to use payment directives, you must carry out the corresponding Customizing in the Implementation Guide: Public Sector Management → Funds Management Government → Funds Management-Specific Postings → Payment Directives
There must be an entry containing the company code, document type, and the payment blocking indicator for invoices.
This entry must also contain the posting key for the document line item , as well as the posting key and the G/L indicator for the offsetting line item to be used for payment directives.
The creation of payment directives is subject to authorizations specified in Customizing. Authorization is checked for the following:
Posting in this company code
Posting in this FM area
Posting and displaying documents according to the FM account assignments involved

In order to use payment directives for postings in Funds Management, the invoice must have an expenditure account with financial transaction type 30 and a vendor with financial transaction type 60.
The following customizing steps refer to the Financial Accounting area of the Implementation Guide or the Financials main menu section, and must be carried out before you can use payment directives:
You must define a document type to be used for posting payment directives. Make the settings to define the document type for payment directives under the following IMG path: Accounting ® Financial Accounting ® Financial Accounting Global Settings ®Document ® Document Header ® Define Document Types.
You must define a special G/L account indicatorin order to post to special G/L accounts. For this, use transaction OBXT Maintain Accounting Configuration (IMG menu: Financial Accounting ® Accounts Receivable and Accounts Payable ® Postings with Alternative Reconciliation Account ® Other Special G/L Transactions ® Define Alternative Reconciliation Account for Customer / for Vendor . Here you can decide which special G/L account will be used when posting with the special G/L indicator.
A special G/L account linked to a commitment item (with financial transaction type 80), maintained under the following main menu path: Accounting ® Financial Accounting ® General Ledger ® Master Records ® G/L Accounts → Individual Processing - Centrally
In order to have the FM update run correctly, you must also make the following Customizing entries:
The FM area must be customized in transaction OF29 Settings for Payment Transfer, (IMG Funds Management Government →Actual and Commitment Update/Integration →Integration ) as follows in the section Processing Mode:
The indicator must be set in the field Deactivate Check on Fiscal Year Change .
You must also checkmark the field Conversion of Bank Clearing .

For more information on the payment selection program, see Payment Selection .