Invoice reductions in Logistics Invoice Verification (RKA)

Question

Hi all,
I´m trying to customize the automatic invoice reductions but I´ve never done before and I don´t know if I´m following the proper steps, so if someone can help me I´d really appreciate it.
This is what I´ve done so far:
1- Obyc. Select Accounts are determined by Debit/Credit
             Posting keys debit 21 credit 50
             Debit account 4xxx Credit account 6xxxxxxx
2. Spro. Log Invoice Verification-> Incoming invoice->Number assig-> Mantain number account document
                    MIRO. document type for invoice reduction KG
3. Spro. Log Invoice Verification-> Incoming invoice->Configure vendor specific tolerances
          I create a tolerance group with automatic invoice reduction
4. I select this tolerance group at the vendor master data of my invoice
5. I create the invoice an select the field vendor error.
When I post the invoice I get the following error:
No account is specified in item 0000000003
Message no. F5670
Diagnosis
No account was specified for account type "K" in item "0000000003" of the FI/CO document.
Thanks and Best Regards

Answer 1

go to SM30 and enter the table V_TF123 hit pencil bitton and maintain the account for account type K
e.g 
Accty = K        from a/c= 0       to account = 9999999999