毎年三月までに前年の所得を税務署に申告しなければならない。
You have to declare the previous year's income to the tax office by March every year.
税関で申告するものは何もありません。
I have nothing to declare at customs.
彼は収入を実際より少なく申告していた。
He had been reporting his income as lower than it actually was.
申告の期限を過ぎると、延滞税がかかることがある。
If you miss the filing deadline, you may be charged a late-payment tax.