The locality for paying over income taxes is the place that each of the following items prescribes, according to which of the cases set forth in those items the taxpayer falls under:
所得税の納税地は、納税義務者が次の各号に掲げる場合のいずれに該当するかに応じ当該各号に定める場所とする。
if the taxpayer is not domiciled in Japan but has a residence there: the place of residence;
国内に住所を有せず、居所を有する場合 その居所地
if the taxpayer is a Nonresident that has a permanent establishment, other than in a case set forth in the preceding two items: the location of the office, place of business, or any other equivalent place relating to the business that the Nonresident conducts through the permanent establishment (or the location of the principal one, if there are two or more such places);
if a person whose locality for paying over taxes was determined under the provisions of item (i) or item (ii) ceases to be domiciled or reside in Japan, and at the time of so ceasing the person does not have an office, place of business, or any other equivalent place relating to the business prescribed in the preceding item, and a relative of the person or any other person specified by Cabinet Order as uniquely related to the person continues to reside, or resides in place of the person, at the place that had been the person's locality for paying over taxes: the place that had been the locality for paying over taxes;
if the taxpayer receives consideration as set forth in Article 161, paragraph (1), item (vii) (Domestic Source Income) (other than consideration for the lending of a ship or aircraft), other than in a case set forth in any of the preceding items: the location of the assets relating to the consideration (or the location of the principal assets, if there are two or more such assets);
前各号に掲げる場合を除き、第百六十一条第一項第七号（国内源泉所得）に掲げる対価（船舶又は航空機の貸付けによるものを除く。）を受ける場合 当該対価に係る資産の所在地（その資産が二以上ある場合には、主たる資産の所在地）
in any case other than those set forth in the preceding items: the place specified by Cabinet Order.
前各号に掲げる場合以外の場合 政令で定める場所
定義第二条第一項第八号の四・法令全体に適用
次に掲げるものをいう。ただし、我が国が締結した所得に対する租税に関する二重課税の回避又は脱税の防止のための条約において次に掲げるものと異なる定めがある場合には、その条約の適用を受ける非居住者又は外国法人については、その条約において恒久的施設と定められたもの（国内にあるものに限る。）とする
わかりやすく言うと
非居住者や外国法人が国内に持つ支店や工場など事業を行う一定の場所、建設や据付けの工事などを行う場所、自分のために契約を結ぶ権限のある者などで、政令で定めるものです。租税条約に異なる定めがあれば、その適用を受ける者については条約で恒久的施設とされる国内のものになります。