Slightly over sq foot to not require permit

In my area, anything 120 sq ft or under doesn’t require a permit. I went down to the building department and confirmed that they measure the “usable space” inside to calculate the 120 sq ft.

Well, of course my pre-fab shed is 123 sq feet inside. Does anyone have an experience with building codes and could tell me whether this 3 sq ft is a problem? I’m not getting it permitted but will likely get a minor permit for electrical eventually.

I also think I can just build out a wall inside to reduce the sq ft to 120, if I had to, but ideally I don’t want to go through the trouble if 123 sq ft is ok. I could ask the building department but not wanting to show my hand, and hoping someone had some advice before I head down there to ask. I guess part of me is expecting them to be strict on the 120 but I don’t have experience to know. Thanks