RingtoniusQuick answer: “Use as Ringtone” only exists on iOS 26 and later, and only appears for a short audio file stored on the iPhone: an MP3 or M4A of 30 seconds or less. If it’s missing, update iOS, download the file from iCloud, trim it to 30 seconds, or convert it to M4A. Then share it again from the Files app or Voice Memos.
1. You’re not on iOS 26 yet
The option was added in iOS 26. Check Settings › General › About. On iOS 18 or earlier, there is no Use as Ringtone; the built-in route is GarageBand’s Share › Ringtone. See how to make a ringtone on iPhone for both methods.
2. The file is longer than 30 seconds
Longer files are refused, sometimes with a “too long” message and sometimes by the option not doing anything. Every iPhone ringtone has to be 30 seconds or less.
3. The file is still in iCloud
If the file shows a cloud icon in Files, it isn’t on the phone yet. Tap it once to download, wait for the icon to disappear, then share again. Files that live only in iCloud, Dropbox or Google Drive can’t be set directly.
4. It’s the wrong kind of file
MP3 and M4A are the formats confirmed to work. WAV, AIFF and other formats may not be offered. Protected Apple Music songs never work, because Apple Music songs can’t be ringtones. Run the file through the ringtone checker to see which problem you have.
5. The share menu is hiding it
Use as Ringtone sits near the bottom of the share sheet’s action list. Scroll all the way down. If it still isn’t there after the steps above, restart the iPhone and try again; a restart clears most share-sheet glitches after an update.