It wasn't free, though — the initial price was £17.49 / $19.99, or less if you wanted GTA Online on its own — but as of June 18th of 2026, they'll now be offering it at no extra charge if you own the digital version of GTA 5 for Xbox One.
Here's the confirmation from Rockstar:
"Beginning tomorrow, those who own any PS4 version or the digital Xbox One version of Grand Theft Auto V will be able to upgrade to the PS5 or Xbox Series X|S versions at no additional cost, and experience the best versions of GTAV and GTA Online ahead of the launch of The Kortz Center Heist."
"GTAV and GTA Online on PS5 and Xbox Series X|S feature vast technical improvements, easy migration of your Story Mode and Online progress, and new features including Hao’s Special Works high-performance vehicles and upgrades, Career Progress rewards, and much more."
As you can see, this coincides with the reveal of The Kortz Center Heist for GTA Online, which will take the form of a multi-stage Heist at some point this summer. No release date has been revealed for it yet.
The curious thing here is that Rockstar says the upgrade applies to "any PS4 version" but only the "digital Xbox One version", suggesting it's just Xbox players that miss out on a physical upgrade for whatever reason.
Anyway, if you happen to own a digital version of GTA V for Xbox One (which includes the "Grand Theft Auto V: Premium Edition") and you haven't upgraded yet, the Series X|S version should appear in your library at some point tomorrow. I've been dipping in and out of it over the past few years and it's definitely an improvement, so perhaps this marks the perfect time to play through the campaign again!