Example:
When applying a payment for a city ledger invoice, you’ve entered the payment type Cash instead of Bank transfer.
Figure 2: Wrong payment type
To correct this mistake, proceed as follows:
Ø Open the client’s profile.
Ø Create a new misc. account (tab Accounts, subtab Misc. accounts).
Ø Highlight the account in the listbox and click Payment in the function pane.
Ø In the Payment-dialog post the amount that went wrong using the payment type Debtor.
Figure 3: Simulate another debtor posting
Ø Settle this account using the payment type Debtor once more.
Figure 4: Settled misc. account
While the Front Office postings are balanced, the city ledger now shows a plus and a minus posting.
Figure 5: Interim status of the city ledger
Ø Highlight the negative posting and click
Apply payment 
to write it off using the wrong payment type Cash.
This balances the postings with payment type Cash.
Ø Highlight the positive posting and click
Apply payment 
to write this
posting off using the correct payment type Bank transfer.
Ø Open the tab Movements to ensure that the postings are balanced and the correction was successful.
Figure 6: Correction successful