Bacs transaction codes explained.
01 - Direct Debit first collection.
17 - Direct Debit regular collection, or credit contra (debit record to balance credit records).
18 - Direct Debit re-presentation.
19 - Direct Debit final collection.
99 - Direct Credit, or debit contra (credit record to balance debit records)
Z4 - Interest payments.
Z5 - Dividend payments.
0N - New instruction.
0C - Cancellation instruction.
0S - Conversion instruction.