The month preceding the current one; the previous month (often used in business or reports).
前月の売上は先月と比べて10%増えた。
Last month's sales increased by 10% compared to the previous month.
このデータは前月分までしかありません。
This data is available only up to the previous month.
前月に提出した書類はすでに処理されています。
The documents submitted last month have already been processed.