PhonesForCash Device Knowledge Centre
Practical guides to identifying, preparing, valuing, testing, selling, reusing and recycling phones — written by the team that inspects and buys devices in person every day at our St Helens counter.
The Device Knowledge Centre is written by the team that inspects and buys devices in person. It's designed to help you:
- › Identify your exact device
- › Understand phone condition and what affects value
- › Prepare your phone for a valuation
- › Protect your data before selling
- › Understand how phones are tested and graded
- › Learn about device reuse and recycling
General guidance — not a confirmed valuation. Last reviewed .
Featured device guides
Helpful starting points — the guides most customers reach for before bringing a phone in.
Featured cluster
Understanding the iPhone Air
Three editorial guides plus the commercial page for anyone weighing up — or already owning — Apple's thin, single-camera iPhone. Last reviewed .
iPhone Air Battery Life: Is It Good Enough?
Endurance, charging and who the Air suits.
OpeniPhone Air Camera: Is One Rear Camera Enough?
What the 48MP Fusion covers — and what it can't.
OpenIs the iPhone Air Worth It?
Thin design, battery, single camera, eSIM trade-offs.
OpenSell Your iPhone Air
Start an iPhone Air valuation at our St Helens counter.
OpenApple Device Preparation
Apple Device Preparation
Different Apple products need different ownership-removal steps. These guides cover Find My, Activation Lock and Apple Account associations across iPhone, iPad, Mac, Apple Watch, AirPods and AirTag. Last reviewed .
Remove Find My Before Selling an Apple Device
Master preparation guide across the Apple ecosystem.
OpenRemove AirPods From Your Apple Account Before Selling
Find My association vs Bluetooth unpairing.
OpenRemove Activation Lock From Apple Watch Before Selling
Unpair correctly, manage the cellular plan.
OpeniPhone Stolen Device Protection Before Selling
Security Delay, familiar locations, what to expect.
OpenWhat Is Activation Lock?
iCloud, Google FRP and MDM locks explained.
OpenHow to Remove Phone Accounts Before Selling
Apple, Google, Samsung, OPPO and HUAWEI sign-out.
OpenA. Selling and Valuation
How second-hand phones are priced — model demand, grading tiers, storage, battery wear, foldable economics, OLED damage and what still has value when a phone is broken.
How Phone Valuations Work
Model demand, grading, battery health and repair deductions explained.
Read guideWhy Storage Size Affects Phone Value
Why 256GB and 512GB models command higher resale offers.
Read guideWhy Battery Health Affects Value
Service messages, cycle counts and how percentages move the offer.
Read guideWhy OLED Damage Reduces Samsung Value
Burn-in, green lines and the cost of replacing AMOLED panels.
Read guideWhy Foldable Phones Depreciate Faster
Hinge wear, inner-display repair costs and limited refurb supply.
Read guideCan Broken Phones Still Have Value?
Refurbishment viability vs parts recovery — when faults still pay.
Read guideB. Device Preparation
Get your phone ready for a clean, confident sale — identify the exact model, check storage and IMEI, back up properly, factory reset safely and handle your SIM or eSIM.
How to Identify Your iPhone Model
Settings, camera layout, connector and frame clues.
Read guideHow to Find Your Samsung Phone Model Number
Galaxy S, A, Z Fold and Z Flip naming explained.
Read guideHow to Check Your Phone's Storage Capacity
Total capacity vs free space — and why it matters.
Read guideHow to Find Your Phone's IMEI Number
Settings, dial-code and packaging methods.
Read guideHow to Prepare Your Phone for a Valuation
Pre-counter checklist for a faster, firmer offer.
Read guideHow to Back Up Your Phone Before Selling It
iCloud, Google, photos, WhatsApp and 2FA apps.
Read guideHow to Factory Reset a Phone Before Selling It
Safe wipe order — sign out before you erase.
Read guideWhat to Do With Your SIM and eSIM Before Selling
Keep your number, clear the device, avoid surprise bills.
Read guideC. Condition and Repair
Understand how your phone will be tested, what condition grades really mean and when a repair will (or won't) recover its cost.
How PhonesForCash Tests a Phone
Step-by-step inspection process at our St Helens counter.
Read guidePhone Condition Grading Explained
Excellent, good, fair, damaged — what each grade covers.
Read guideShould You Repair or Sell a Damaged Phone?
Cost-of-repair vs working / broken resale value framework.
Read guideWhat Is Activation Lock?
iCloud, Google FRP and MDM locks — and how to clear them safely.
Read guideD. Reuse and Recycling
Reuse, refurbishment, parts harvesting and materials recycling — what each one means and why extending a device's life is usually the better outcome.
E. Ownership and Upgrade Decisions
The questions phone owners actually ask — performance after an update, when to upgrade, whether launches really hurt resale, how third-party repairs affect value and when an old phone stops being safe to keep using.
Why Is My iPhone Slower After an iOS Update?
What's temporary, what's battery, what's hardware.
Read guideWhen Should You Upgrade Your Phone?
A scorecard for repair, replace or keep going.
Read guideDoes a New Phone Launch Reduce Resale Value?
Selling before or after launch — what actually changes.
Read guideDo Third-Party Repairs Affect Phone Value?
Parts quality, service messages and disclosure.
Read guideIs Your Phone Too Old to Use Safely?
Updates, banking apps, battery safety and reliability.
Read guideiPhone Air Battery Life: Is It Good Enough?
Real-world endurance, charging and who the Air suits.
Read guideiPhone Air Camera: Is One Rear Camera Enough?
What the 48MP Fusion camera covers — and what it doesn't.
Read guideIs the iPhone Air Worth It?
Thin design, battery, single camera and eSIM trade-offs.
Read guideF. Selling Safely & Account Security
Everything that protects you, your data and the buyer when ownership of a phone changes hands — checklists, brand-by-brand account removal and Apple's Stolen Device Protection. Works whether you're selling privately, on a marketplace, to a trade-in service or at our counter.
What to Do Before Selling Your Phone
Master checklist covering backups, accounts, SIMs, locks and proof of sale.
Read guideHow to Remove Phone Accounts Before Selling
Apple, Google, Samsung, OPPO and HUAWEI sign-out in the right order.
Read guideRemove Find My Before Selling an Apple Device
iPhone, iPad, Mac, Apple Watch, AirPods and AirTag — the master Apple-device preparation guide.
Read guideRemove AirPods From Your Apple Account Before Selling
AirPods, AirPods Pro and AirPods Max — Find My association vs Bluetooth unpairing.
Read guideRemove Activation Lock From Apple Watch Before Selling
Unpair correctly, deal with the cellular plan and clear Activation Lock.
Read guideiPhone Stolen Device Protection Before Selling
Security Delay, familiar locations and what to expect at the counter.
Read guideWhat Is Activation Lock?
iCloud, Google FRP and MDM locks — and how the owner clears them.
Read guideHow to Find Your Phone's IMEI Number
Settings, dial-code and packaging methods.
Read guideHow to Back Up Your Phone Before Selling It
iCloud, Google, photos, WhatsApp and 2FA apps.
Read guideHow to Factory Reset a Phone Before Selling It
Safe wipe order — sign out before you erase.
Read guideWhat to Do With Your SIM and eSIM Before Selling
Keep your number, clear the device, avoid surprise bills.
Read guideG. AirPods, Apple Accessories & Authenticity
AirPods authenticity, packaging, serial numbers and the difference between a hardware reset and removing the previous owner's Apple Account. Written for owners selling AirPods, AirPods Pro and AirPods Max.
Sell AirPods
AirPods, AirPods Pro and AirPods Max — face-to-face authentication and same-day payment in St Helens.
Read guideHow to Tell If AirPods Are Fake
Construction, software, audio and component-matching checks for AirPods and AirPods Pro.
Read guideHow to Tell If AirPods Max Are Fake
Materials, Digital Crown, audio, serials and packaging on the over-ear flagship.
Read guideCan AirPods Serial Numbers Be Faked?
Why a recognised serial is useful evidence but not standalone proof of authenticity.
Read guideRemove AirPods From Your Apple Account Before Selling
Reset vs account removal — why resetting alone is not enough.
Read guideReady for a guide price on your specific device?
These guides explain the logic. For a real number on your model, message the team or visit our St Helens counter. General guidance is not a confirmed valuation.