アメリカ国内であれば関税はかからないようですが、場合によって必要になることがあるようです。
その為、お客様より事前に関税へ問い合わせ頂き確認頂いた方がより確実かと思います。
IT seems that if it's within the States there won't be any customs tax but there are cases that it will be necessary.
That is why, I think it will be more reliable if it was the customer who will make inquiries about the customs tax for me in advance.
