Associate a Taxonomy term to user who creates it I have field Company Name which is a term reference to a vocabulary with same name. when user types the field if name already exists, so auto complete showed that or else it will be added as taxonomy term. let us consider "BBB" is the company name he entered.

On next scenario when another user keying in this company name as "BBB" so its already their in the taxonomy so i have to send a mail to the user who created added the term "BBB" first.

I tried using rules module but i couldn't find way to get the user who created the term.Meanwhile i use Profile2 module so writing submit handler is best?
Taxonomy doesnt contain this kind of data.
A possible workaround would be-
Creation of a custom module that writes data into a custom table. 
You can use hooks to intercept the addition of the item.