What does a balance of payments deficit mean?

It implies the existence and value of money. According to this theory, a deficit in the balance of payments is a mechanism that adjusts an excess supply of money between the instance and recording of a transaction. In the short-term, a balance of payments deficit isn't necessarily bad or good.

Why does the balance of payments not balance out?

This often results in short-term deficits or surpluses from excess payments or receipts. In other words, the transactions that are recorded in the current and financial accounts might not balance out because of irregularities with the capital account. The balance of payments is theoretically a monetary phenomenon.

Can a current account sustain a deficit in the balance of payments?

The current account is just one part of the overall balance of payments, which also contains the capital account and financial account. According to theory, it's impossible to sustain a deficit in the balance of payments. In practice, temporary imbalances do occur because of accounting difficulties.