Topics related to universal accounting principles and best practices, local GAAP, audit, laws and regulations affecting financial reporting, and other financial reporting topics.
This is also the appropriate forum for beginners to ask any questions, even if they pertain to IFRS.
Guess you'd look at it in the definition of incidental costs when thinking about what goes into amortised cost accounting, if not then bank charges perhaps - keep it simple
interest expense is not defined in IFRS, I would follow JRSB's thinking. If it's part of the amortised cost, it's interest expense. If not, treat it as other charges. However, nothing stops you to recognise those charges as finance costs (interestingly: finance costs are required to be presented separately by IAS 1.82(b), but are not currently defined in IFRS).