Top 7 Things to Check Before Buying a Used iPhone in 2025

With iPhone prices soaring and tech evolving rapidly, many savvy buyers are turning to the second hand iPhone market for premium features at affordable prices. Whether you're looking for an iPhone 13, 14, or even the newer iPhone 15 series, buying used can save you big—if you know what to look for.

But not all second hand phones are equal. A bad purchase can leave you stuck with hidden issues, blacklisted devices, or poor battery life. At Control Z, we help customers buy second hand iPhones with confidence—by inspecting, verifying, and restoring each device professionally.

In this blog, we’ll guide you through the top 7 things to check before buying a second hand iPhone in 2025 to make sure you get real value for your money.

1. Check the IMEI/Serial Number for Blacklist or Theft

Before anything else, verify the IMEI (International Mobile Equipment Identity) or serial number of the iPhone. This number is unique to each device and can reveal if the phone is:

• Reported stolen

• Blacklisted

• Under carrier lock

• Still under warranty

How to check:

Go to Settings → General → About and note the IMEI and serial number. Use Apple’s Check Coverage or third-party IMEI checkers to confirm the phone's status.

At Control Z, every second hand iPhone we sell is thoroughly IMEI-verified and guaranteed not to be blacklisted or stolen.

2. Inspect for Activation Lock (iCloud Lock)

One of the most common scams in the second hand iPhone market is selling a device that’s still tied to someone else’s Apple ID. This is called Activation Lock, and if it’s active, you won’t be able to use the phone at all.

How to check:

Ask the seller to erase the iPhone completely and go through the setup screen. If the phone asks for the previous Apple ID and password, the lock hasn’t been removed.

Control Z ensures that all second hand iPhones are factory reset and 100% iCloud-unlocked before resale.

3. Test the Battery Health

Battery life plays a critical role in your iPhone’s performance. Apple throttles devices with weak batteries to prevent shutdowns. So, buying a second hand iPhone with poor battery health means you might end up spending more on battery replacement soon.

How to check:

Go to Settings → Battery → Battery Health & Charging. Look for the Maximum Capacity and Peak Performance Capability.

• If capacity is below 85%, it’s likely you’ll need a new battery soon.

• If it says "Service," a battery replacement is due immediately.

At Control Z, we ensure all batteries meet performance benchmarks or are replaced with genuine, high-quality parts.

4. Inspect for Physical and Screen Damage

Scratches, dents, and cracked screens may seem cosmetic, but they often point to rough use or drops that could impact internal components. Pay special attention to:

• Screen brightness, color tint, or unresponsive areas

• Back glass or frame damage

• Face ID or Touch ID functionality

Test key components like:

• Camera (front and back)

• Microphone and speaker

• Power and volume buttons

• Charging port and headphone jack (if available)

• Face ID / Touch ID authentication

Control Z refurbishes second hand iPhones professionally—replacing broken parts and ensuring flawless screen, camera, and sensor performance.

5. Verify Network Compatibility and SIM Unlock Status

In 2025, most carriers use VoLTE and 5G networks. A phone that’s locked to a specific carrier or not compatible with Indian network bands may lead to dropped calls, slow data, or even no service.

How to check:

• Insert your SIM and test calls and data.

• Go to Settings → General → About → Carrier Lock – it should say No SIM restrictions.

If you’re buying online or from a seller in another country, this check is crucial. At Control Z, all second hand iPhones are sold fully unlocked and tested on major Indian networks.

6. Check Storage, Model, and iOS Compatibility

Don’t assume you’re getting the model the seller claims. Check the exact model number and verify its specs online. Also, ensure it supports the latest iOS version for better security and app compatibility.

How to check:

• Go to Settings → General → About

  • Model Number: Confirms if it’s an Indian version or imported

  • Storage Capacity: Make sure it matches the listing

  • iOS Version: See if it supports the latest updates

Control Z clearly lists every second hand iPhone’s storage, region, and software compatibility before sale—so there are no surprises.

7. Buy from a Verified or Trusted Source

This is perhaps the most important tip: where you buy your second hand iPhone matters more than what you buy.

Avoid vague listings on classified websites, social media, or sellers unwilling to meet in person or offer receipts.

Instead, choose platforms like:

• Certified Refurbishers (like Control Z)

• Reputed e-commerce platforms with buyer protection

• Authorized resellers or trade-in stores

At Control Z, we go beyond second hand sales. Every iPhone undergoes:

• 45+ point quality checks

• Professional cleaning and refurbishment

• Battery and screen diagnostics

• 6-month warranty & return policy

Plus, you get transparent pricing, real-time chat support, and the peace of mind of buying from a trusted tech brand.

Bonus Tip: Ask for Invoice and Warranty

A legitimate seller will always give you a purchase invoice or ownership transfer document. This not only proves that you’re the legal owner but also helps in service center visits and resale later.

With Control Z, every second hand iPhone comes with:

• Official tax invoice

• 6-month warranty

• Option to extend coverage

Conclusion

Buying a second hand iPhone is a great way to enjoy Apple’s ecosystem without burning a hole in your pocket. But to truly make it a smart investment, you must verify its authenticity, performance, and ownership.