Balance b/f on Supplier statement (transactions)

i had entered an invoice on a date earlier than the starting date , but the supplier statement shows the invoice as being made on the starting date, rather than a balance brought forward.

That is because the start date is the date the transaction was applied to supplier’s account. Manager uses pre-start-date transactions to establish the Accounts payable balance, but before the start date, there can be no balance. So what the statement reports is not the invoice’s issue date, but the date it was applied by the program. If you are migrating from another accounting system (the only reason you should set a start date), the issue date of the invoice is recorded in the previous system, not Manager.