What the message is
Since iOS 15.2, every iPhone 11 and newer keeps a short repair log under Settings, General, About, Parts and Service History. When a part is replaced, the log shows one of three labels next to it: Service (the part was verified and paired by Apple’s process), Used (an original part taken from another iPhone) or Unknown Part. The Unknown Part label is what a customer sees after almost any repair done with aftermarket parts, and it is the single most common question a repair shop gets after handing a phone back.
Apple’s own wording is that the label appears when the part is not an original part, has not been verified and linked to the phone after the repair, was modified, or is not working as expected. In practice, for a shop installing an aftermarket screen or battery, it simply means the phone cannot read the pairing data it expects.
Which parts and which models
The log does not cover every component. What is tracked depends on the model.
| Model | Tracked parts |
|---|---|
| iPhone XR, XS, XS Max, SE (2nd and 3rd gen) | Battery only |
| iPhone 11 series | Battery and display |
| iPhone 12 and newer | Battery, display, front camera, rear camera, logic board |
| iPhone 16 and newer | Same, plus back glass and enclosure can be configured in Repair Assistant |
Charging ports, speakers, buttons, back glass on older models, housings and flex cables are not tracked. Replacing those parts does not produce any message, whatever the source of the part.
When the customer sees it
There are two places. First, a notification on the lock screen the first time the phone is unlocked after the repair, and a second one about five days later. After that the notifications stop. Second, the permanent line under About, which stays for the life of the phone unless the part is later replaced with a paired original one. On iOS 15.1 and earlier the same situation produced an “Important Display Message” or “Important Battery Message” banner instead.
What it actually affects
This is the part worth explaining to customers calmly. The Unknown Part label by itself does not block the phone. Calls, cameras, Face ID, Apple Pay and updates keep working. The limitations that do exist come from the missing pairing, not from the label:
- Display: True Tone is switched off unless the display data was transferred with a programmer, and on some models auto-brightness may behave differently. See True Tone after screen replacement.
- Battery: on older iOS versions the Battery Health screen showed “Unable to verify” and no maximum capacity figure. Since iOS 18.1 most aftermarket batteries report health again, but the log still says Unknown Part unless the battery chip is matched. Details in battery health and cycle count.
- Cameras: an unpaired rear camera may show a message and, on some models, lose features such as portrait depth control. The front camera is tied to Face ID hardware; see camera replacement notes.
- Logic board: a board from another phone is marked Unverified and can lose Apple Pay. This is not a repair-shop scenario with our parts and is mentioned only for completeness.
Repair Assistant and used original parts
From iOS 18 the phone runs Repair Assistant when it detects a replaced part. With an original part pulled from the same model (what our catalogue calls Original or Refurbished Original) the assistant can calibrate the part on iPhone 15 and newer over Wi-Fi, after which the log shows Used instead of Unknown. With aftermarket screens that carry the original IC and sensors transferred over, the phone often records no history at all. Aftermarket batteries do not pass Repair Assistant; health data shows, but the label stays. This matters when you choose grades for a job: a customer who cares about a clean log needs a Refurbished Original screen and a pull battery, and should be told the price difference up front.
How to explain it at the counter
- Say before the repair that the phone will show a note in Settings and two notifications, and that it does not affect function.
- Show the customer the About screen after the repair so the note is not a surprise later.
- Write “aftermarket display installed, pairing note in Settings is expected” on the receipt. This protects you when the phone is sold or traded in later.
- Do not promise that a programmer removes the label. True Tone transfer fixes True Tone, not the log.
What does not help
Restoring iOS, resetting settings or swapping SIM cards does nothing. Battery chips marked “no pop-up” that spoof original serial numbers hide the battery notification on some iOS versions, but the behaviour changes between updates and we do not describe such batteries as problem-free in our listings. Our batteries are labelled Original Chip, Health-Tested or Pre-Programmed (JCID) so you know what the phone will read; see the iPhone parts catalogue.
Safety note
A part marked Unknown is not unsafe by definition, but a part that fails its self-test is reported the same way. If a replaced battery shows Unknown Part together with heat, rapid drain or swelling, stop using the phone and replace the battery rather than reasoning about the label.
FAQ
Does the Unknown Part message go away on its own?
The two notifications stop after about five days. The line under Settings, General, About stays until the part is replaced with a paired original part.
Will Face ID stop working because of an unknown display?
No. Face ID depends on the TrueDepth module, not on the display pairing. If Face ID fails after a screen job, look for a damaged or unseated flex, not the label.
Can a programmer remove the Unknown Part line?
No. Tools like JCID V1SE and QianLi iCopy transfer True Tone and battery data, which fixes the features. The log entry is decided by the pairing check and stays.
Does the message lower the trade-in value?
Some trade-in and refurbisher programmes check the log and grade the phone lower. Tell the customer this if they plan to sell the phone soon.
Which parts can I replace without any message?
Charging ports, speakers, buttons, vibration motors, housings, back glass on models before iPhone 16 and all flex cables. Find them under iPhone Parts.