‘In office’ vs. ‘in the office’ vs. ‘at the office’ in English

Tip: See my list of the Most Common Mistakes in English. It will teach you how to avoid mis­takes with com­mas, pre­pos­i­tions, ir­reg­u­lar verbs, and much more.

After I published my article about being in/at school, one of my readers asked me about the difference between “in office” and “at office”.

What we would normally say is either “in the office” or “at the office” (notice the definite article). The preposition “in” in “I am in the office” implies that the office is a room and you are inside that room. The word “at”, on the other hand, conveys the general idea of the location of one’s office and is often interchangeable with “at work”. To sum it up:

I am in my/the office. = My office is a room and I am in that room.
I am at my/the office. = I am somewhere near my office or in it. I am at work.

“In office” (without an article) means something quite different. We say that someone is “in office” when they work in an official position, usually for the state. For example, we could say:

Bill Clinton was in office from 1993 to 2001.

when referring to his presidential post.

Finally, “at office” (without an article) isn’t common usage. If you feel the urge to say “at office”, say “at the office” instead:

correct I am not at the office right now.

unnatural I am not at office right now.