iPhone 18 Mistakes New Owners Make: 9 Things to Avoid

October 6, 2026

Buying a new iPhone 18 is exciting.

You transfer your data, sign into your Apple Account, choose your wallpaper and start using it almost immediately.

But there are a few things most people don't think about until it's too late.

From skipping important settings to leaving your new screen exposed, there are several common mistakes iPhone 18 owners make during the first few days that can affect your privacy, security, battery, photos and even the long-term condition of the phone.

Whether you've bought the iPhone 18 Pro, iPhone 18 Pro Max or another model in the new generation, here's what you should check before simply carrying on as normal.

1. Not updating your iPhone straight away

One of the biggest mistakes is assuming that a brand-new iPhone doesn't need an update.

It does.

Apple's iOS 27.0.1 update already addressed several issues affecting the iPhone 18 Pro and iPhone 18 Pro Max, including unexpected restarts related to Face ID, a camera colour artefact and an issue where opening Notification Centre and Control Centre simultaneously could make the touchscreen unresponsive.

So one of the first things you should do after setting up your iPhone 18 is:

Settings → General → Software Update

Apple also recommends keeping automatic updates enabled because software updates provide new features, bug fixes and security improvements.

Don't make the mistake of thinking "it's brand new, so it's already up to date."

The first software version installed on a new phone isn't necessarily the latest version available.

Give your iPhone a few minutes to check.

It could save you from running into a problem that Apple has already fixed.

2. Transferring everything without checking your old phone first

Quick Start makes moving to a new iPhone incredibly easy.

You can place your old iPhone beside your new one and transfer apps, settings and other information. Apple recommends keeping both devices nearby and connected to power until the migration is complete.

But there's a mistake hidden inside the convenience.

People often transfer everything without checking what they're actually transferring.

Your old iPhone may contain:

Apps you haven't used in years
Old downloads
Thousands of unnecessary photos
Outdated settings
Apps you forgot you installed
Notifications you no longer want
Old Home Screen clutter

Your new iPhone is an opportunity to clean things up.

Instead of blindly recreating your old phone, take a few minutes to decide what you actually want to keep.

3. Not making sure your backup actually works

This is one of the mistakes you'll only regret when something goes wrong.

Before getting rid of your old iPhone, make sure your information is safely backed up.

Apple's iCloud Backup can automatically back up your iPhone daily when it's connected to power, locked and connected to Wi-Fi.

You can check your backup through:

Settings → [Your Name] → iCloud → iCloud Backup

If you're moving to your new iPhone and don't have enough iCloud storage, Apple also offers eligible users temporary iCloud storage specifically for transferring data to a new device.

Don't erase your old phone until you're confident everything you need is on the new one.

4. Leaving the default settings untouched

Your iPhone 18 is designed to work out of the box.

That doesn't mean the default settings are necessarily the best settings for you.

iOS 27 introduces a huge number of customisation, privacy, security and AI-related features.

Take some time to go through:

Settings → Privacy & Security

Settings → Notifications

Settings → Battery

Settings → Camera

Settings → Apple Account

You don't have to change everything.

But spending 15 minutes going through the important settings can make your iPhone feel completely different.

5. Ignoring the new security features

This is one of the most overlooked things about setting up a new iPhone.

iOS 27 introduces Impersonation Risk Detection, a security feature designed to help identify suspicious activity associated with scams.

When enabled, supported third-party apps can use the feature to receive a risk assessment when you're performing potentially risky actions such as making a payment or changing important security information.

You can find it under:

Settings → Privacy & Security → Impersonation Risk Detection

Apple says the underlying information used to generate the risk level is analysed on-device, while supported apps receive the resulting risk level rather than the underlying information.

It's not a replacement for common sense or two-factor authentication.

But if you're buying a brand-new phone in 2026, there's little reason not to understand the security tools available to you.

6. Treating the iPhone 18 Pro camera like an older iPhone

If you've bought an iPhone 18 Pro or iPhone 18 Pro Max, you're leaving a lot on the table if you simply point and shoot.

Apple's new Pro camera system introduces variable aperture, giving users more control over the way photographs and videos are captured.

On iPhone 18 Pro models, you can manually control:

Aperture
Shutter speed
White balance
Exposure
Histogram

Apple also allows the aperture setting to be preserved between camera sessions.

You don't need to become a professional photographer.

But learning what aperture actually does can make a noticeable difference when you're shooting portraits, low-light scenes or subjects where you want more control over depth of field.

A simple place to start

Open the Camera app and experiment with the aperture setting.

Take the same photograph at different aperture values.

You'll quickly see how changing the aperture can alter both exposure and the amount of the scene that appears in focus.

That's one of the major reasons to buy the Pro model in the first place.

7. Assuming the screen is protected because you have a case

This is probably the most expensive mistake on the list.

You spend over a thousand pounds on a new iPhone and immediately put it into a case.

It feels protected.

But look at your phone again.

What's actually covering the display?

With many traditional phone cases, the answer is: nothing.

The case protects the back and edges while the display remains exposed to scratches, impacts and everyday damage.

And then there's privacy.

Someone sitting next to you on a train, plane or in a coffee shop can still see what's on your screen.

That's why the approach of simply buying a case + a separate screen protector isn't necessarily the best solution anymore.

8. Buying a cheap case just because it fits

Your iPhone 18 is one of the most expensive objects you carry around every day.

So it makes little sense to spend a significant amount on the phone and then choose the cheapest case available simply because it fits.

A case should be evaluated on more than appearance.

Consider:

How much of the phone does it actually protect?
Does it protect the display?
Does it work with MagSafe?
Does it protect the cameras?
Does it interfere with the touchscreen?
How does it handle drops?
Will the material yellow over time?
Does it provide any privacy?

The cheapest case isn't necessarily the cheapest option if you end up replacing it — or your phone — later.

9. Using a separate screen protector when you don't need to

A traditional setup usually looks like this:

iPhone → screen protector → phone case

That means two separate accessories, two installation processes and another layer between you and the display.

The Techterio Privacy Case takes a different approach.

Its two-piece design combines a protective case with a built-in privacy screen, giving you front and rear protection while making your display difficult to see from the side.

From directly in front, the screen remains visible.

From an angle, the privacy filter makes the display appear dark.

It also works with MagSafe and is designed to provide protection around the phone while eliminating the need for a separate screen protector.

Why this matters more than you might think

Your screen isn't just where you watch videos and scroll through social media.

It's where you access:

Banking apps
Emails
Messages
Photos
Passwords
Work information
Personal conversations
Authentication codes

A normal case protects the phone.

A privacy case can protect what you're looking at on the phone too.

If you're regularly using your iPhone in public, that's a meaningful difference.

Shop the Techterio Privacy Case for iPhone 18 Pro →

10. Forgetting that physical damage isn't a software problem

There's a strange contradiction with buying a brand-new iPhone.

We worry about software bugs, battery health, updates and settings — but often neglect the one thing we can actually control from day one:

physical protection.

Apple has already released iOS 27.0.1 to address several early iPhone 18 Pro software problems.

Software problems can often be fixed with an update.

A cracked display can't.

That's why your protection strategy should start before the first drop, not after it.

The smarter way to set up your new iPhone 18

You don't need to spend hours changing every setting on your new iPhone.

Start with these:

Before you leave the house

1. Update iOS

Check for the latest software and install it.

2. Verify your backup

Make sure your important information is safely backed up.

3. Transfer your data properly

Use Quick Start or an appropriate backup rather than manually rebuilding everything.

4. Review privacy and security

Check the permissions and security features available in iOS 27.

5. Learn the new camera

Especially if you bought the iPhone 18 Pro or Pro Max.

6. Protect the display

Don't wait until after the first scratch or drop.

7. Think about privacy

Your screen can reveal far more than you realise when you're using your phone in public.

The one mistake you can't undo

Most of these mistakes are easy to fix.

Forgot to change a setting?

You can change it.

Didn't explore the camera?

You can learn it.

Didn't enable a security feature?

You can enable it.

But physical damage is different.

Once your brand-new iPhone has a cracked or badly scratched display, there's no setting that will undo it.

That's why protecting the phone before something happens is so much better than trying to deal with the consequences afterwards.

The Techterio Privacy Case is designed around that idea.

Instead of adding a conventional case and then putting another accessory over the display, it combines front protection, rear protection and built-in privacy into one two-piece design.

It also supports MagSafe and is designed to eliminate the need for a separate screen protector.

Protect your iPhone 18 Pro with the Techterio Privacy Case →