when they are talking about the deficit or surplus they are usually only talking about the current account. The balance of payments will balance because the other accounts in it (Capital, financial...
As per the accounting rule "For every Debit there should be a Credit" and that is how balance sheet tallies where Liabilities is Debit and Asset is Credit.
Given that it reflects all payments and liabilities to foreigners and all payments and obligations received from foreigners, the balance of payments is one of the major indicators of a country's...