The two settings are not the same
Settings → General → Software Update → Automatic Updates contains two controls. Download iOS Updates fetches the update in the background but waits for you. Install iOS Updates is the one that applies it overnight while the phone is charging.
If your complaint is waking up to a new version you did not ask for, turn off Install. If your complaint is the storage an unwanted staged update is occupying, turn off Download as well — otherwise iOS will keep re-fetching it after you delete it.
Leave security responses on
Below the two switches is Security Responses & System Files. This delivers targeted security patches between full releases, and they are small, fast and specifically for actively exploited vulnerabilities.
Turning it off is a genuinely bad trade. It is the one part of the automatic update system worth keeping on even if you want complete control over major versions.
Deleting an update that has already downloaded
Turning off automatic updates does not remove one already staged. Settings → General → iPhone Storage lists the iOS update as its own item; tap it and choose Delete Update to reclaim the space and clear the badge.
If the badge comes back within a day, Download iOS Updates is still on. Both switches need to be off for the cycle to stop.
Why the red badge persists
The Settings badge counts an available update, not an installed one. It stays until you either install or delete the update, and there is no supported way to hide it while an update is pending.
Our guide to clearing update prompts covers this in more detail, including what to do if you are also enrolled in a beta channel.
When to turn them back on
Automatic updates are the main reason ordinary iPhones receive security patches promptly, and most people who turn them off never turn them back on. If your reason was a single bad release or a beta cycle, put a reminder somewhere to re-enable them afterwards.
A middle path that works well: leave Download on, Install off. Updates arrive quietly and wait, and you choose the moment — which is usually all people actually wanted.
Frequently Asked Questions
How do I stop my iPhone updating overnight?
Settings → General → Software Update → Automatic Updates, then turn off Install iOS Updates. Leave Download on if you want updates ready but not applied.
What is the difference between Download and Install iOS Updates?
Download fetches the update in the background and waits. Install applies it automatically overnight while charging.
Should I turn off Security Responses too?
No. Those are small, targeted patches for actively exploited vulnerabilities and are worth keeping on even if you control major updates manually.
How do I delete an update my iPhone already downloaded?
Settings → General → iPhone Storage, select the iOS update and choose Delete Update. Turn off Download iOS Updates as well or it will return.