Can I sell a flight and a hotel together as one holiday package instead of two separate bookings?

Yes, in most setups you can put a flight and a hotel together and sell them as one holiday, with a single price and a single confirmation for the traveller. The portal searches each part in the background, then shows the combination as one item in the basket, so the customer sees one total to pay instead of two separate amounts.

Behind the scenes the two parts are still held with their own suppliers, and that matters because each one keeps its own rules. The hotel may be free to cancel up to a certain date while the flight becomes non refundable the moment it is ticketed, so the terms you show for the package have to follow the stricter of the two. It is far better to put that in front of the customer before payment than to explain it afterwards.

How much you can bundle depends on what you have connected and on your plan. Many agencies also want to drop a transfer, a day tour or their own contracted hotel into the same package, and that is usually possible, although anything you supply yourself has to be loaded and priced by you rather than pulled from a supplier. Where a supplier does not permit its rates to be sold inside a package, that content will simply not appear as an option in the search.

Before you start promoting packages, build one for a route you already sell often, then read the cancellation wording that comes out at the end so you know exactly what you are committing to if the customer changes their plans.