Join Date: Dec 2000
Location: Charleston, SC, USA
Programs: Avis Pref+, Hyatt Explorist, Marriott Life Gold, Honors Silver, IHG Plat via MC.
Posts: 6,786
Eethan, you can do it without a problem as long as your AC & your relative's US are not already linked to 2 different points.com accounts. Also, provided your AC & your own US are not already in your own points.com account.
Say if your points.com contains your AC & NO US, then just add your relative's US to your own points.com, declaring his/ her name correctly. Then do the transfer.
Or if neither your AC nor his/her US is linked to points.com, you can open up a new points.com account with a secondary email address, link only those 2 accounts to it, then do it.