Quick answer: A properly refurbished phone needs to pass checks across display, battery, connectivity, biometrics, housing, and network status before it's ready for resale — not just "does it turn on and look okay." Below is a full 15-point checklist covering every area a buyer (or a marketplace's own inspection) is likely to scrutinise, plus a simple margin calculation to check the refurbishment is actually worth doing before you start.
Why a proper checklist matters more than it used to
Used and refurbished phones are a growing share of the overall smartphone market, and buyers in this category tend to be more informed and more price-sensitive than average — many are specifically comparing refurbished listings against each other, not just against new devices. A missed fault that surfaces after sale doesn't just cost you a return; it costs you a review, and reviews are disproportionately influential in a market where buyers are actively looking for red flags before committing.
The 15-point refurbishment checklist
- Display and touchscreen. Check for dead pixels, discolouration, backlight bleed (LCD) or burn-in (OLED), and full-panel touch responsiveness including the very edges.
- Battery health. Check maximum capacity against the manufacturer's threshold for the phone's age, and note it clearly in the listing rather than leaving buyers to guess.
- Charging and data connection. Test wired charging, wireless charging if supported, and data transfer via cable — not just "does it charge," but "does it charge at the expected rate."
- Cameras. Test every lens (front, main, ultra-wide, telephoto, macro where applicable) for focus, image quality, and any visible marks on the lens glass or sensor.
- Speakers and microphones. Test call audio, speakerphone, and any secondary microphones used for noise cancellation — a fault here is easy to miss in a quick visual inspection.
- Face ID, fingerprint sensor, or other biometrics. Confirm enrolment and recognition works reliably, not just that the sensor is physically present.
- Wi-Fi, Bluetooth, and mobile signal. Test all three separately — a phone can have perfect Wi-Fi and a weak or faulty mobile antenna, which won't show up unless you specifically test cellular signal.
- Housing and back glass. Check for cracks, deep scratches, bent frames, or gaps at the seams that could indicate previous water exposure or a poorly-fitted repair.
- Buttons and vibration motor. Test every physical button and confirm haptic feedback/vibration works as expected — a sticking button is a common, easily-missed fault.
- Liquid damage indicators. Most phones have LDI stickers inside the SIM tray or battery compartment that change colour on water exposure — check these and disclose if triggered, even if the phone currently works fine.
- Network or activation locks. Confirm the phone is not reported lost or stolen, is fully carrier-unlocked if advertised as such, and has no outstanding account locks (Find My, Google/Samsung account locks) that would prevent a new owner from setting it up.
- Parts and Service History. Check what shows here (on supported iPhone models) and disclose any Unknown-status parts honestly — see our full explainer on Genuine, Used and Unknown part status.
- Adhesive and seals. If the phone has had a screen or battery replacement, confirm new adhesive was used and the assembly sits flush, with no gaps that could let dust or moisture in.
- Cleaning and cosmetic grading. Clean thoroughly (including ports and speaker grilles), then grade honestly against a consistent standard — "like new," "good," "fair," or similar — rather than optimistic guesswork.
- Final functional test after reassembly. Run through every check above one more time after any repair work and reassembly, since a working component can be accidentally disturbed during other repairs on the same device.
The margin calculation you should run before refurbishing
Not every unit is worth refurbishing to resale-ready condition — the maths should confirm it before you invest the time:
Estimated gross profit = expected selling price − purchase cost − replacement parts − labour − expected returns allowance
Run this before committing significant repair work, particularly on units needing multiple simultaneous repairs. A phone needing a screen, battery, and charging port might still be worth refurbishing if the purchase cost was low enough, but the same repairs on a unit you paid full trade-in value for could easily turn into a loss once parts, labour, and a realistic return-rate allowance are factored in.
Real parts commonly needed during refurbishment
Screens:
- iPhone 14 FHD LCD screen — from £18.99
- Samsung Galaxy A15 OLED screen — from £28.99
Batteries and adhesives:
- Samsung Galaxy S24 replacement battery — from £10.34
- Battery adhesive strips — from £1.99
Charging and connectivity:
- iPhone 16 charging port flex cable — from £14.99
- Samsung Galaxy A01 charging port board — from £4.99
Tools:
- 10-in-1 repair tool kit — from £0.99
Common refurbishment mistakes worth avoiding
- Testing components in isolation instead of after full reassembly. A speaker that tests fine before the back cover goes on can develop a rattle or muffled sound once everything is sealed — always run the final functional test after the unit is fully reassembled, not before.
- Assuming a visual pass means a functional pass. A screen with no visible marks can still have degraded touch sensitivity at the edges. A camera lens with no scratches can still have a focus motor issue. Test function separately from appearance for every item on the list.
- Skipping the liquid damage indicator check because the phone "obviously" hasn't been wet. LDIs can be triggered by humidity exposure over time, not just submersion, and a triggered indicator is exactly the kind of thing a buyer's own inspection will catch if you don't disclose it first.
- Reusing old adhesive to save a small cost. This is one of the most common causes of a battery or screen working loose within weeks of resale, turning a completed sale into a return or a bad review over a component that cost very little to do properly the first time.
- Not checking activation/network lock status until after other repair work is done. If a unit turns out to be locked, that's often a dealbreaker regardless of condition — check this first, before investing time in cosmetic or component repairs on a unit that may not be resaleable at all.
- Grading optimistically rather than consistently. A grading standard only works if it's applied the same way to every unit — inconsistent grading erodes buyer trust faster than conservative grading does, even when the conservative grading occasionally undersells a genuinely good unit.
What buyers actually check before purchasing a refurbished phone
Understanding buyer behaviour helps prioritise where to spend your refurbishment effort. Informed buyers in the used and refurbished market commonly check, in roughly this order: battery health percentage, cosmetic grade photos (specifically looking for undisclosed damage), IMEI/lock status via a free online checker, seller reviews and return policy, and only then price. This ordering matters — a phone with excellent battery health and an honest cosmetic grade will often sell at a fair price faster than a cheaper phone with vague or missing information on those same points, because buyers in this category are actively trying to avoid the specific problems this checklist catches.
Building a consistent grading standard
Buyers trust consistent grading language more than optimistic individual descriptions. Define your own tiers clearly and apply them the same way every time:
| Grade | Typical criteria |
|---|---|
| Like new / Grade A | No visible marks under normal inspection, battery health above a set threshold, all functions pass without exception |
| Good / Grade B | Minor cosmetic marks not affecting use, battery health within acceptable range, all functions pass |
| Fair / Grade C | Visible wear or marks, may include a lower battery health reading disclosed upfront, all core functions still pass |
| Fault disclosed | Any known issue not fixed — always disclose rather than hoping it goes unnoticed |
Step-by-step: a repeatable refurbishment workflow
- Run the full 15-point checklist before doing any repair work, so you know exactly what needs fixing.
- Check the network/activation lock status first — a locked device is a dealbreaker regardless of everything else, so confirm this before investing further time.
- Calculate expected margin using the formula above before committing to repairs.
- Complete repairs in a logical order — typically battery and charging first (so you can properly test the device throughout the rest of the process), then screen, then cosmetic/housing work.
- Re-run the full checklist after all repairs and reassembly are complete.
- Grade consistently against your defined standard and photograph honestly — including any disclosed marks.
- List with a clear, accurate description of grade, battery health, and any part status considerations.
Frequently asked questions
Do I need to disclose an Unknown Part status even if the phone works perfectly?
Yes — buyers increasingly check this themselves, and being upfront about it builds more trust than having it discovered after sale. Most buyers understand that Unknown status doesn't mean poor quality once it's explained.
How important is battery health specifically to resale value?
Very — it's one of the first things informed buyers check, and a low reading without disclosure is one of the most common sources of post-sale disputes. If battery health is below a reasonable threshold for the phone's age, replacing it before sale is usually one of the best-value refurbishment steps you can make.
What's the most commonly missed item on this checklist?
Liquid damage indicators and network/activation lock status — both require a specific, deliberate check rather than showing up in normal handling, and both can be dealbreakers if discovered after sale rather than disclosed upfront.
Should I refurbish every unit I acquire, or skip some?
Run the margin calculation first. Units requiring multiple simultaneous repairs, or units you paid close to full working-condition value for, may not be worth refurbishing to a high grade — sometimes selling as-is with an honest fault disclosure is the better financial decision than sinking parts and labour into a low-margin unit.
How long should a proper refurbishment take per unit?
This varies by how many repairs are needed, but the checklist itself — testing every point without any repair work — typically takes a focused 20-30 minutes once you're familiar with the process. Build this into your time and cost estimates rather than treating it as a quick final glance before listing.
Is it worth replacing a battery that's still above 80% health before resale?
Usually not purely on health grounds if it's already above the threshold buyers typically look for, but disclose the exact reading regardless — buyers value knowing the real number over assuming it's fine. If the reading is close to the threshold and you expect the unit to sit in inventory for a while before selling, replacing proactively can avoid a borderline reading becoming a problem by the time it actually sells.
Should I keep records of the checklist results for each unit?
Yes, and this is worth building into your workflow from the start rather than adding later. Keeping a simple record of pass/fail results, battery health readings, and any parts replaced per unit protects you if a buyer disputes a fault after sale, and it also helps you spot patterns over time — for example, a particular model or repair source consistently having issues with one specific checklist item is exactly the kind of trend you'd otherwise only notice anecdotally.
Summary
A proper refurbishment checklist covers far more than "does it turn on" — display, battery, every connectivity type, biometrics, housing integrity, liquid damage indicators, and lock status all need individual checks. Run the margin calculation before committing to repairs on any given unit, grade consistently against a defined standard, and disclose honestly — in a market where buyers are actively comparing refurbished listings, transparency is what earns repeat business and good reviews. Keep records of every check per unit — it protects you against disputes and helps you spot patterns in fault rates over time that a purely anecdotal approach would miss.