What is the actual common reading of その他? Is it そのほか or そのた? Are there differences in social or grammatical context, or a nuance in the actual meaning?

  • スーパー大辞林 doesn’t list その他 as a word. There is an example with その― for ほか, but not for た.
  • ウィズダム和英辞典 lists そのほか only as a link to そのた.
  • Yomikatawa simply says そのほか.
  • Weblio contains some entries beginning both with そのほか and そのた, some of them with the other as a variant and others without it. By itself it is listed as そのほか with そのた as a variant.

I wasn’t able to abstract any rule, but I’m still not sure whether they’re freely interchangeable.