Samsung's One UI 9 schedule slipped twice in a week. One carrier shipped it anyway

Two days ago, we covered Samsung's One UI 9 rollout and flagged the specific dates circulating for the S25, Z Fold7 and Z Flip7 as coming from a single market's newsroom — Thailand's — rather than a global commitment. That caution held up faster than expected. Samsung's own Thailand schedule did not survive the week.

What the schedule said, and how it changed

Thailand's original posting had the Galaxy S26 series getting the update internationally on September 21, with the S25 series and the Z Fold7 following on September 28. September 21 came and went with no update reaching S26 owners outside Korea. Samsung then revised the S26 date to September 28, folding it in with the S25 and Z Fold7 rather than sending it first. That revision did not last either: on September 22, Samsung's Thailand newsroom removed the specific date altogether, and now simply says the update arrives "within September" for the S26, S25 and Z Fold7 lines. Samsung has not published an explanation for either change.

The update itself did not wait for a date

While the written schedule was being revised twice in two days, the actual software started moving. On September 23, Galaxy S26 Ultra units on T-Mobile in the US began receiving the stable One UI 9 build over the air — a roughly 4.1GB download carrying the September 2026 security patch, according to reporting on the rollout. Other US carriers had not received it as of that report; AT&T was expected within a day or two, and unlocked units and other S26 configurations on T-Mobile itself were still waiting too.

That is the part worth sitting with: the phones that actually got the update this week did not arrive on the date Samsung had written down, on either version of it, and they arrived through a specific carrier rather than as a blanket release. A newsroom date describes Samsung's plan. A build reaching your phone describes what happened. This week, those were two different things.

Why one carrier moves before the others

A carrier variant of the same phone does not update on Samsung's calendar alone — it needs that carrier's own certification pass first, and carriers run those checks on their own schedule and in their own order. That is a routine part of how US Android updates have always worked, and it is the most likely reason T-Mobile's S26 Ultra units moved while AT&T's, Verizon's and the unlocked model were still waiting a day later. It also means the gap between carriers this week says nothing about which one Samsung favors, and nothing about whether the S25 or Z Fold7 lines are close behind — those are separate certification queues, each running at its own pace.

What this means if you are still waiting

Nothing about the delay changes what One UI 9 actually contains — the Now Brief cards, the Warranty and Care panel, the wider Scam Detection rollout, all of it is the same software described when the rollout first began. What changed is how much weight to put on any specific date Samsung publishes before the update is in your hand. If you are on an S26 and use T-Mobile, check for the update now; if you are on another carrier or another model, a published date this week is not a stronger signal than it was two days ago, and the safer read is still "when it arrives" rather than "on the date." For the S24 line and older foldables, nothing here moves the October estimate from our earlier piece either way — there is still no date to revise.

Last updated September 24, 2026