I have a single line of text column in my list called "Invoice Number" which only needs to contain numeric characters (0-9).
I have attempted using column validation with =ISNUMBER([Invoice Number]+0)
However using this formula still allows for the use of symbols. As long as there is at least 1 number in the text box it will allow you to save the item with the following symbols - . + £ $
everything I have found online suggests using the formula above but is there anyway to tweak this formula to prevent the use of these symbols?