A tax office (government agency) that handles tax procedures, consultations, and filings.
確定申告のために税務署に行った。
I went to the tax office to file my tax return.
税務署から通知が届いたので、書類を持って相談に行くつもりだ。
I received a notice from the tax office, so I plan to take the documents and consult with them.
副業の収入について税務署に確認した。
I checked with the tax office about income from my side job.