FlyerTalk Evangelist, Ambassador: World of Hyatt
Join Date: Jul 2001
Location: NJ
Programs: Hyatt Globalist, Fairmont Lifetime Plat, UA Silver, dirt elsewhere
Posts: 46,919
Look on your corporate travel site under hotels. You should find a list of preferred hotels and their codes.
If they don't list the codes, try to make a dummy booking at a hotel, and it should fill in automatically.
At worst, call your corporate travel dept.