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Before paying for a used iPhone or Samsung Galaxy flagship, verify that it is free of account locks, works as described, supports your carrier, and still receives security updates. Inspect the actual phone, check battery and repair information where available, and understand the seller’s return terms. A reset or a clean-looking exterior alone cannot establish that a phone is ready for you to use.
Before you arrange the sale
Identify the exact phone and check support
Confirm the model, storage capacity, and regional variant—not just the product family name. Ask your intended carrier whether that exact model will work on its network and with the SIM or eSIM setup you plan to use. Imported variants can differ, so do not assume that a phone sold under the same flagship name is compatible.
Check the manufacturer’s current software-update support for the exact model. The UK National Cyber Security Centre advises avoiding phones that are no longer supported, or whose support is nearing its end, when possible. Its guidance directs Samsung owners to check with the manufacturer. Support status can vary by model and region, so verify it rather than relying on the phone’s age or the seller’s description. NCSC second-hand-device guidance
Get useful evidence from the seller
- Request recent photos of the actual device: screen on and off, corners, back, camera area, and charging port.
- Ask the seller to disclose defects, repairs, battery condition or warnings, and which accessories are included. Request repair receipts or service details when available.
- For an online purchase, check who the seller is, who handles returns, the deadline, eligible reasons, shipping costs, and how refunds are issued.
- Use the marketplace checkout and a payment method covered by its buyer-protection rules. Paying outside the marketplace may remove that protection.
- Ask for the phone’s IMEI and check it with your intended carrier or the appropriate official service in your market. There is no single IMEI or blacklist checker established here as authoritative across countries and carriers.
The FTC advises marketplace buyers to check refund and return rules, find out who can help if something goes wrong, and use a safe payment method. Return windows can be short, so confirm the terms before ordering. FTC guidance on buying from an online marketplace
The Tool Desk
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- 6.1", 1080 x 2340pixels, Infinity-O FHD+ Dynamic AMOLED 2X Display, 3700mAh Battery, Wireless Powershare
- 128GB ROM, 8GB RAM, No SD Card Slot, Qualcomm SM8450 Snapdragon 8 Gen 1 (4 nm), Octa-Core, Adreno 730
- Rear Camera: 50MP, f/1.8 + 10MP, f/2.4 + 12MP, f/2.2, Front Camera: 10 MP, f/2.2, Android 12, One UI 4.1
- CDMA 800/1900, 3G: HSDPA 850/900/1700(AWS)/1900/2100, CDMA2000 1xEV-DO, 4G LTE: 1/2/3/4/5/7/8/12/13/14/18/19/20/25/26/28/29/30/38/39/40/41/46/48/66/71, 5G: 1/3/5/7/8/20/28/38/41/66/71/260/261SA/NSA/Sub6/mmWave - Single SIM
- Compatible with Most GSM and CDMA Carriers like T-Mobile, AT&T, MetroPCS, etc. Will Also work with CDMA Carriers Such as Verizon, Sprint.
Check the phone itself
Inspect the exterior and test basic functions
At an in-person sale, remove the case if possible. In an online purchase, do these checks as soon as the package arrives and while the return window is open. Look over the display, frame, back, camera glass, and charging port for cracks, dents, corrosion, debris, or signs of a poorly fitted repair. Apple’s pre-owned iPhone guide recommends inspecting the display, sides, back, and connector. Apple’s guide to buying a pre-owned iPhone
Power on the phone and connect it to a charger. Apple says not to buy an iPhone that will not charge. Give the phone a brief ordinary-use check: test touch response across the display, brightness, cameras, speakers, microphones, volume and power buttons, vibration, Wi-Fi, and charging connection. On a Galaxy, ask the seller to demonstrate the same functions; these are practical checks, not a substitute for model-specific Samsung diagnostics.
Watch for an unstable connection or an abrupt shutdown during ordinary use, but do not treat a brief check as a complete battery diagnostic. If buying online, photograph defects or discrepancies and contact the seller or marketplace promptly, before the return deadline.
Rank #2
- This phone is unlocked and compatible with any carrier of choice on GSM and CDMA networks (e.g. AT&T, T-Mobile, Sprint, Verizon, US Cellular, Cricket, Metro, Tracfone, Mint Mobile, etc.).
Make sure the phone is not tied to someone else’s account
For iPhone: do not buy a phone with Activation Lock enabled. Ask the owner to turn it off before payment. If an online purchase displays “iPhone Locked to Owner,” Apple says to return it.
For Galaxy: have the seller remove their Google and Samsung accounts and any anti-theft protections, then reset the phone and let you proceed through setup. A wipe by itself is not proof that the phone is ready; setup must not remain tied to another person’s account. Samsung Canada’s trade-in terms identify Google Account, Samsung Account, Find My Mobile/Reactivation Lock, and Knox among protections that must be removed or turned off for that program. Those terms corroborate relevant lock types but are not a complete buyer guide. Samsung Canada trade-in terms
If the seller refuses a basic demonstration, a reset, or clear written return terms, walk away or choose a sales channel with enforceable buyer protection.
Rank #3
- Display: 6.2" AMOLED display with 120Hz refresh rate and 1300 nits brightness for vivid visuals and smooth scrolling.
- Camera: Rear dual camera system with 64MP main and 12MP ultrawide lenses for stunning photos and videos.
- Memory: 128GB internal storage and 8GB RAM for plenty of apps and files.
- Connectivity: 5G capable with support for GSM, CDMA, and Wi-Fi networks.
- Battery: 4000mAh battery provides all-day power for your daily needs.
Check iPhone battery, repair, and carrier information
Parts and Service History
On an iPhone, open Settings > General > About and look for Parts and Service History. This section may appear on iOS 15.2 or later, depending on the model and repair. “Genuine Apple Part” indicates replacement using genuine Apple parts and processes. “Unknown” can mean a part was not installed completely, is nongenuine or previously used, or is not working as expected. Treat an Unknown status as a reason to ask questions and request service details—not proof of fraud.
Battery Health
Open Settings > Battery > Battery Health; on iOS 16.1 or later, the label may be Battery Health & Charging. Apple says iPhone 6 and later running iOS 11.3 or later can show battery health and replacement recommendations. Health information may not be available for an unknown or nongenuine battery, and older devices or different repair histories may not show identical information.
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Rank #4
- Connectivity Technology: NFC
- Operating System: Android 13.0
- Memory Storage Capacity: 512.0 GB
- Camera Description: Rear
- Battery Charge Time: 79.0 minutes
Carrier lock
Go to Settings > General > About > Network Provider Lock. Apple says No SIM restrictions means the iPhone is unlocked; a named provider indicates a carrier restriction. If the seller claims the phone has been unlocked, confirm that directly with the relevant carrier. A carrier-unlocked phone still needs to be compatible with your carrier’s network and your intended SIM or eSIM setup.
Know when to stop the purchase
- Activation Lock is on: require the iPhone owner to disable it before you buy; return an online iPhone that shows “iPhone Locked to Owner.”
- Galaxy setup is still tied to another person: do not proceed unless the seller removes the account or protection and you can continue through setup.
- The phone will not charge or the seller blocks a reasonable test: do not rely on assurances in place of a working demonstration.
- The price is dramatically below comparable listings or the photos are stock images: pause and verify the actual item and seller. The FTC warns that unusually low prices can be a sign of a fake listing and recommends checking actual-item photos. FTC marketplace guidance
- Support is ending or has ended: reconsider whether the remaining security-update runway suits your planned ownership period.
- Repair history is unclear: ask what was repaired and request receipts or service information. An iPhone “Unknown” part status is not, by itself, evidence of wrongdoing.
These checks reduce avoidable risks, but they do not guarantee that a phone is not stolen, unpaid, blacklisted, or blocked after sale. Use the IMEI check available from your carrier or an appropriate official service in your market.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Compare offers on more than the asking price
Use the same factors for each phone so a low price does not hide costs or a weaker remedy.
Best Value
- Pro-Grade Camera: The new Samsung Galaxy S20 FE mobile phone features high-powered pro lenses for beautiful portraits, stunning landscapes and crisp close-ups in any light with its 3X optical zoom
- 30X Space Zoom: Whether you want your cellphone to zoom in close from afar or magnify details of something nearby, 30X Space Zoom gives you the power to get closer
- Night Mode: Capture crisp images and vibrant video with Night Mode and create high-quality content in low light — no flash required with this smartphone
- Single-Take AI: One tap of the screen captures multiple images and video all at once; Lenses, effects and filters capture the best of every moment, every time
- Power of 5G: Get next-level power for everything you love to do with Samsung Galaxy 5G; More sharing, more gaming, more experiences and never miss a beat
| What to compare | Questions to ask |
|---|---|
| Total cost | What is the price after shipping and taxes? Will you need a battery, screen, or port repair, or a missing charger or cable? |
| Condition and repair transparency | What wear or defects are visible? Do all tested functions work? Are repair details or manufacturer repair indicators available? |
| Battery | Is health information available? Are there warnings or a disclosed replacement? What remedy does the seller offer if the battery disappoints? |
| Lock and carrier readiness | Have account and activation locks been removed? Does the exact phone work with your intended carrier? |
| Security-update runway | Does the manufacturer still support this exact model and regional variant? |
| Buyer recourse | Who is the seller? What return period, warranty, refund process, and protected payment method apply? |
Compare a used phone with certified refurbished
Certified refurbished can cost more than a private-sale handset, but the disclosed warranty, battery, and return terms may make the trade-off worthwhile. Samsung’s US Certified Re-Newed page says those phones are refurbished by Samsung using genuine Samsung parts, receive a certified new battery, and include a one-year limited warranty. The page also states a 15-day return period, subject to terms and possible restocking fees; lists compatibility with specified US carrier types; and identifies a data cable and ejector pin among included box items. Check the live listing and terms before purchase: these are Samsung US program claims, not guarantees about used Samsung phones generally or terms for other countries. Samsung US Certified Re-Newed program
Compare those exact terms with the private seller’s price, the device’s condition and repair history, and the return or warranty remedy offered. Warranty coverage, consumer rights, and return policies vary by country and seller; Apple’s cited buying guide is UK guidance, Samsung’s refurbished program details are US-specific, Samsung’s trade-in terms are Canadian, and the FTC guidance is US consumer advice.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
