You work as a Service Desk Agent at ABC company (not real) with several different sites across the country. An employee or user calls in and wants to have his/her password changed.
You ask him/her:
Which site are you based in?. Is this correct?
Thanks so much for the help.
Thanks so much for your suggestions. But you did not answer the question.
I can't think of one, because the accepted preposition after "based" (when talking about this kind of location) is "at".
There are different prepositions which follow "based" in different contexts:
Which country are you based in?
Which site are you based at?
What is your assumption based on?
You also can be based out of somewhere.
Which country are you based out of?
Which site are you based out of?
I don't think this works though:
What is your assumption based out of?