A significant number of Account Numbers and Sort Codes must be Transposed from the form in which they are issued to the Payer into the form required by Bacs for the actual processing of the Direct Debit or Direct Credit payments. This transposing must take place prior to Modulus Checking.
Approximately 11%* of account numbers will need to be transposed.
Here are some examples:
- 10 digit account numbers which require conversion to 8 digits plus the generation of an additional account code
- 9 digit account numbers which require conversion to 8 digits together with a modification to the sort code
- Account numbers of less than 8 digits which require padding to 8 digits
- Account numbers of greater than 8 digits - depending on the institution, it is either the first or last 8 digits which are required
- 12 digit building society account numbers containing alpha characters - these must be converted to valid 8 digit account numbers through the use of a 'look-up' table
* Bank Wizard figures 2002
Transposing in action
Here are some examples of transposing. These examples show how Experian Payments’ Bank Wizard undertakes the conversion automatically.
This GiroBank account number needs converting from a 9 digit account number to 8
Here we can see that the first digit of the account number is used to modify the last digit of the sort code, leaving the final eight digits for the account number. This example shows how a 12 digit alpha-numeric Bradford & Bingley Time Save Account (which does support Direct Debits) needs converting to 8 numerics.
The first six digits of the final eight digits are selected with the 08 being derived from a code look-up table.