How to use a Global Upgrade Certificate (GUC)

Understanding the (shitty) changes to the Delta Air Lines Global Upgrade Certificate program.

The race to the bottom is in full throttle at Delta Air Lines by devaluing a choice benefit for their top-tier frequent flyers. Global Upgrade Certificates (GUCs) allowed a Diamond Medallion to book any main cabin (fare classes V, X, T, U, L, K, Q, H, M, B, Y) or Delta Comfort+ (fare class S) and apply use a GUC to move them up to First Class or Delta One.

Savvy Diamond Medallion members could book deeply discounted tickets for a few hundred dollars and use these certificates to upgrade to the Delta One cabin for free – a well deserved and earned perk for frequent flyers spending a minimum of $15,000 in flights with Delta Air Lines.


Effective February 1, 20022 Delta Air Lines changed the rules for redemption of GUCs requiring that both a Premium Select cabin (fare classes G, A, P, F) be purchased and there must be fare class Z available in order to clear into Delta One.

The up-side

There’s isn’t much here, except that if fare class Z is available you can immedaitely confirm into Delta One at the time of booking.

How to use the system to your advantage

The following recommendations have been heard/seen in the wild – YMMV.

If you see a flight with both Premium Select and Delta One fare class Z availability, buy main cabin and hope for an upgrade offer to Premium Select. If you take the upgrade to Premium Select, you’ll be in a fare class that is eligible to apply a GUC to Delta One. Again, assuming fare class Z is still available, call reservations and have them apply and clear the GUC.

Frequently Asked Questions (FAQ)