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The following explains when the balance will be displayed positively or negatively.
if If a line item on a transaction results in a credit balance for the Accounts Payable Account the amount on the Vendor Balances page will be displayed positively, for example $100.00.
If a line item on a transaction results in a debit balance for the Accounts Payable Account the amount on the Vendor Balances page will display negatively, for example ($100.00).
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