In NZ, your bank account number is formatted like XX-XXXX-XXXXXXX-XXX
The first two groups (6 digits) is bank and branch number (don't enter dashes)
The second two groups are the account number and suffix. Some banks give you 3 digit suffix but use only the last two digits.
Basically, if your account number is 12-1234-0123456-000, you'd enter it as bank number or code "121234", account number "0123456-00".