Could you add the cost to my room bill?
FYI: This Japanese sentence may sound odd to some learners, but it actually sounds very natural.
- 会計 means either “accounting” (financial activity) or “a bill”.
- つける or 付ける as a verb means “to attach”, basically. But つけ as a noun means “an outstanding bill” in a financial context. It’s derived from 書き付け (to take a note not to forget something".
So, 会計をXにつけて下さい means “I don’t pay the cost at this very moment. Please take a note of my outstanding financial liability. And then send the bill to me later by combining with X”.