Writing english digits vs. Japanese Kanji

I have seen Japanese text where predominantly, english digits (e.g. 1, 2, 3, and so on) are used in the context instead of Japanese Kanji. When does a person use english digits vs. Japanese Kanji to represent digits?

Whenever you want to use either of them, just use it. There are no restrictions regarding this as far as I know :).

Thank you! I was told, or so I believe, that Kanji is used when characters are written vertically whereas english digits are written horizontally. Has anyone heard of that?

I heard about this too, but I've also seen vertical writing with english digits, so I don't think it's a strict rule or anything like that

Basically, you will either see english or Kanji numbers depending on the type of product, sign, place, etc. In Japan, you will usually see romanized digits (usually written horizontaly) on "newer" things. For example, you will rarely (if ever) see something at a 7/11 that has Kanji numbers instead of romanized numbers. In addition, Japanese people will usually use romanized numbers when listing prices, labeling items, etc. Generally, the only time you will see Kanji numbers is at older places (like temples for example) and at traditional, fancy restaurants (usually used to list the prices of meals or on their signs).