Open the reservation wish to link to another reservation:
Navigate to the itinerary tab
Select the itinerary line that needs to be linked
Click on More Actions and then Link. You will require supervisor rights to do so.
Search for the reservation to which you wish to link the itinerary to and select it
The confirmation window will appear asking for confirmation and advising that the current reservation will become a house account
Click on house account
If you are linking a Group Reservation to another Group Reservation, then the above steps will need to be done until all the itinerary lines have been linked accordingly. The last itinerary line to be linked will give the confimration window to change the reservation to a house account.