National Australia Bank has booked additional charges of A$1.2 billion ($1.7 billion before tax) for customer remediation, as well as a change to the application of its software capitalisation policy.In a statement to the ASX yesterday, the bank said the impact on September half earnings would be a reduction of around $1.1 billion after tax.The remediation portion of the charge is $832 million. The provision covers potential customer refunds of adviser service fees paid to self-employed advisers.The bank has made 450,000 remediation payments to customers so far. Of the latest charges, more than 90 per cent are for wealth and insurance.The total provision for customer remediation now stands at $2.1 billion. The bank said it now has in place "provisions for the estimated costs and customer payments relating to all known material customer remediation matters based on information currently available."