Folio

The running bill attached to a stay. Every charge a guest incurs, the room rate, taxes, breakfast, the minibar, a spa treatment, a late checkout fee, posts to the folio and settles at departure.

"Folio posting" is the ability of an outside system to add a charge to that bill. It is a small-sounding capability that shapes daily operations: a spa, restaurant or activity system that cannot post to the folio has to take payment separately, which breaks the single bill guests expect, or relies on somebody re-keying the charge into the PMS later. The second option is where revenue quietly goes missing.

Properties often split a stay across several folios, for example one for charges the company pays and one for the guest's own extras, which is known as folio splitting or routing.

For vacation rental and short-stay operators the equivalent concept usually appears as the reservation's charges or ledger rather than as a folio, but the principle is the same.