Are there any rates that you cannot use your UG certificates on?
 

I used to avoid third party sites for booking because I didn't get stay/night credits but that benefit is no longer relevant. So, are there rates that you cannot call the hotel and apply your UG certificates to? Currently, I'm unable to get into my Fairmont account (since the Accor "upgrade") or I'd go read the T & C's.

I think I've booked through places like Delta Vacations previously and still called and applied the certs but does anyone have a definitive answer? The hotel I'm looking at has a great deal on a flash deal site - the site is reputable but I'd like to use certs to updated.

TIA!