Users do not want to sit around waiting for on-request products to be confirmed. More likely than not they are booking on a mobile device whilst already on holiday. To achieve the above you will need to be connected to your suppliers API. If they don’t have an API it could be possible to scrape the supplier’s public website or their agent portal.
If you are a supplier yourself, then you want to have as many of your agents as possible booking directly into your system via an API. Most off the shelf travel systems will come with an API already, but if not then you should consider building one. It’s not as difficult as it sounds – the technology part of it is actually very easy. The difficulty and delays will always be caused by your data – if your system is set up for internal use only, then suddenly exposing it to the outside world may cause you to expose more than you bargained for – like your net rates.