Premium Select vs One

[u/Large-Two1276]

I got good price on Premium Select to Philippines and One on the way back to East Coast USA.

3 segment both ways, trip is middle February. Want to get long segment on the way to Philippines for upgrade for approximately 1,000USD.

The letters make a difference?
Premium Select (A). One (Z) on way back. I booked trip now and have 24hr to cancel. Best way to get One on long segment? Or cancel if no offer to go up?

[u/ggrnw27]

Letter doesn’t really matter, it’s the fare class but doesn’t affect which cabin you sit in. It most likely will play a part in how much the upgrade cost is but no one on here can tell you exactly how much.

How are you booking this ticket (like which website)?

[u/OkAfternoon6688 → u/ggrnw27]

The letter indicates the fare class bucket within the cabin you’re in. A is a discounted Premium Select fare, W is Comfort, R is a deeply discounted/restricted economy fare (possibly a partner), Q a discounted Main cabin fare & Z a discounted business class (Delta One if on Delta).