Can I tell from the flight search results whether a fare is refundable before I book it?

Yes, in most cases you can, although how much detail you get depends on the airline and the type of fare. Most flight search results come back with a marker showing whether the fare is refundable, non refundable, or changeable for a fee, and that marker can be shown right next to the price on your site so your staff and your customers can see it before anyone commits.

For the full picture there is usually a separate step that pulls the airline's own fare rules for the exact fare you have chosen. Some airlines send this back in a tidy, structured form with the change and cancellation conditions clearly separated, which means you can display them neatly on your quote or checkout page. Others send back long blocks of legal text written for ticketing staff, and all you can really do is show it as it is. Low cost carriers often keep it very simple and just tell you the fare cannot be refunded at all.

Be aware that the refundable marker describes the fare family, not a promise about what will happen in a particular case. What a customer actually gets back can depend on how close to departure they cancel, whether any part of the journey has been flown, and the airline's policy at that moment. Even on a non refundable ticket some taxes may come back. A firm figure is normally only available at the point you actually request the cancellation.

When you set up your portal, compare a refundable and a non refundable fare side by side in testing, then decide where on your pages that status should appear so nobody books the wrong one by accident.