In some exam questions there are separate requirements for substantive procedures for payables and substantive procedures for purchases, how do you differentiate between the 2 sets of procedures?
Payables = balances owed to suppliers. Procedures will include reconciling individual balances to control account, reconciling ledger balances to supplier statements, perhaps a payables circularisation, tracing payments to suppliers after period end from cash book to ledger.
Purchases = expense in nominal ledger. Trace postings to that account to purchase day book totals; trace PDB entries to invoices, ensure invoices properly analysed (VAT excluded usually), trace to orders etc.