Hi all. I can't find an answer on very simple question. What's the difference, if I book expenses on vendor bill using service item or expense category? Will I have any limitation somewhere in future if I use expense category instead of expense item?

I’d say the only difference is if you’re trying to reconcile time entries as service items are used to record time, so it’s apples to apples. But expense category is really just to dumb down the expense accounts for non-accountants, but AP should know the expense accounts anyway.