Upselling Customer portal
The Customer portal allows you to upgrade guests' reservations even before they check-in.
Cost items
The first option you have is upselling via cost items. The cost items reflected in the Customer Portal are those set to 'Selection by guest' and 'To be selected during reservation as during upgrade of existing reservation'. Examples of these types of cost items are breakfasts, children chairs or an extra towel package. Using auto emails you can remind the guest that they can upgrade their reservation.
Upgrading a reservation in the Customer portal can be done up to the moment the guest checks in. This can no longer be done during a reservation.
Widgets
The second option you have is upselling via widgets. Widgets can link to external parties, from a bike rental or a restaurant, for example. You can read all about adding widgets here.