iPhone dialer codes attracted 7,122 likes and 347,000 views on a single X post in 2026. The appeal is obvious: your phone has hidden menus that Apple does not document, and the curiosity is completely justified. Several of these codes reveal information that is genuinely useful rather than just novel, and a few open diagnostic views that were designed for technicians but work fine for consumers who know what they are looking at.
This guide covers the codes that actually work on current iPhones running iOS 17 and iOS 18, what each one shows, and the specific situations where you would actually want to use them.
How to Use iPhone Dialer Codes
Open the Phone app, tap the Keypad tab, and type the code exactly as shown. Most codes execute immediately when you finish entering them, without pressing the call button. A few require pressing call to initiate. The codes use only numbers, asterisks (*), and hash symbols (#).
You cannot bookmark these, and they do not appear in your recent calls list. They are entered fresh each time. Some codes open a persistent menu that stays visible until you close it; others flash a result and disappear. The behavior is noted below for each code.
One important note: several codes that circulate online as “iPhone secret codes” are actually GSM standard codes that work on any phone on any carrier, not iPhone-specific features. Others are carrier-specific and may produce different results depending on whether you are on AT&T, Verizon, T-Mobile, or another network. This list distinguishes between the two categories.
*3001#12345#* : Field Test Mode (The Most Useful One)
This is the code that gets shared most often, and it is genuinely useful. Enter *3001#12345#* and press Call. This opens Field Test Mode, a diagnostic interface originally designed for Apple engineers and carrier technicians to assess device radio performance.
What you see in Field Test Mode depends on your iOS version. On iOS 16 and later, it opens a three-pane interface showing LTE/5G signal data, serving cell information, and neighbor cell information.
The most immediately useful number is in the Serving Cell Measurements section. Look for rsrp0 (reference signal received power). This is your actual cellular signal strength expressed as a negative number in dBm, typically between -50 dBm (excellent) and -120 dBm (barely functional). The bars on your iPhone’s status bar are a carrier-tuned visual representation of this number that varies between carriers and can be optimistic. The raw dBm number does not lie.
Use cases for Field Test Mode that are genuinely practical: comparing actual signal strength between two locations in your home to find the best spot for a Wi-Fi call before an important meeting. Checking whether your 5G connection is actually 5G NR (new radio) or 5G NSA (non-standalone, which is 4G LTE with a 5G label in many cases). Testing whether a carrier SIM in a new area is giving you usable signal before committing to service. Diagnosing whether a weak signal is a coverage issue or a hardware issue on your specific device.
Exit Field Test Mode by pressing the Home button or swiping up to close the app. The menu does not persist after closing.
*#06# : Display Your IMEI Instantly
Enter *#06# and your IMEI (International Mobile Equipment Identity) appears immediately without pressing Call. No navigating to Settings, then General, then About, then scrolling. The IMEI is a 15-digit number that uniquely identifies your iPhone hardware, separate from any SIM card.
Why you actually need your IMEI: if your iPhone is stolen and you report it to your carrier, they use the IMEI to blacklist the device from activating on any network. Having your IMEI recorded before a theft makes this process instantaneous rather than requiring you to access your Apple ID account remotely. It is also required when selling your iPhone to verify it has not been reported stolen, and when claiming insurance for a damaged or lost device.
The *#06# code typically shows multiple IMEIs on dual-SIM iPhones: one for each SIM slot. The MEID (Mobile Equipment Identifier used in CDMA networks) may also appear. Note the IMEI1 number and store it separately from your phone, ideally in your password manager alongside your iPhone serial number.
For additional iPhone diagnostic information that does not require dialer codes, Settings, General, About shows your serial number, model number, software version, and carrier information all in one place. But *#06# remains the fastest path to IMEI when you need it quickly.
*#07# : SAR (Radiation) Level
Enter *#07# and press Call. This opens the regulatory information screen showing your iPhone’s SAR (Specific Absorption Rate) values. SAR measures the rate at which your body absorbs radio frequency energy from the device, measured in watts per kilogram of body tissue.
The FCC limit for mobile phones in the United States is 1.6 W/kg averaged over 1 gram of tissue. Apple reports SAR values for head exposure and body exposure separately, and modern iPhones typically come in below these limits with significant margin. The values shown by *#07# are the same values Apple publishes in its regulatory filings; the code just surfaces them without requiring you to find the documentation.
This is genuinely informational rather than alarming. Carrier and regulatory bodies require this disclosure on all devices sold in their markets. If you are comparing SAR values between devices or simply curious what yours shows, this is the direct path. The page also includes links to RF exposure guidelines.
*#21# : Check If Call Forwarding Is Active
Enter *#21# and press Call. This displays the current status of call forwarding on your line. The result shows whether unconditional call forwarding is active and, if so, to which number your calls are being redirected.
This is a GSM standard code that works on any carrier, not iPhone-specific. The reason it matters: call forwarding can be enabled without your knowledge in some scenarios, including during SIM swap attacks where a fraudster convinces your carrier to forward your calls to a number they control. This is used to intercept two-factor authentication codes delivered via phone call. Checking *#21# costs 30 seconds and tells you immediately whether your calls are going where you expect.
A clean result showing “Not active” or similar confirmation from your carrier means no unconditional forwarding is set. If you see an active forward to a number you do not recognize, contact your carrier immediately. To disable call forwarding: dial ##21# (note the double hash at the start) and press Call. This deactivates unconditional forwarding via the GSM standard command.
*#62# : Check Voicemail Forwarding Number
Enter *#62# and press Call. This shows the number your calls are forwarded to when your phone is unreachable, which is typically your carrier’s voicemail system. Most users see their carrier’s voicemail number here.
The security use case: if this number has been changed to something other than your carrier’s official voicemail number, it indicates possible call forwarding manipulation. The number shown should match your carrier’s documented voicemail access number. AT&T voicemail is typically 1-800-288-2020. T-Mobile routes to 1-805-637-7243. Verizon routes to 1-800-922-0204. If the number in the *#62# result is different from your carrier’s voicemail number and you did not set it, call your carrier.
*225# : Check Account Balance (AT&T Prepaid)
Enter *225# and press Call. On AT&T prepaid accounts, this returns your current account balance via SMS or a screen notification. This is a carrier-specific code, not a universal iPhone feature.
T-Mobile’s equivalent is #225#. Verizon prepaid uses *611 to reach customer service for account inquiries. Carrier-specific codes vary significantly and are worth checking on your specific carrier’s support site if you have prepaid service and want quick account info without opening an app.
##002# : Disable All Forwarding
Enter ##002# and press Call. This GSM standard code deactivates all call forwarding rules on your line: unconditional forwarding, busy forwarding, no-answer forwarding, and unreachable forwarding simultaneously.
Use this code as a first response if you suspect your calls are being intercepted or if you are troubleshooting call delivery issues after changing carriers or SIM cards. It is a clean-slate reset for forwarding rules that takes 5 seconds and is reversible if you intentionally had forwarding set up.
*646# : Check Data Usage (T-Mobile)
Enter *646# and press Call on a T-Mobile line. This returns your current billing cycle data usage summary via SMS. For users on tiered data plans rather than unlimited, this is a quick way to check remaining data without opening the T-Mobile app or logging into My T-Mobile.
The AT&T equivalent is *3282# (*DATA#), which sends a usage summary SMS to your AT&T number. These carrier-specific codes are less commonly known than they should be and remain useful when you need quick data status checks during a call or in a situation where opening an app would be inconvenient.
Codes That Do Not Work on iPhone (Despite Widespread Claims)
Several codes circulate widely as iPhone features that do not actually work on current iOS devices.
*#62# for IMSI retrieval does not work on iPhone. The IMSI (International Mobile Subscriber Identity) is stored on the SIM and is not accessible through iOS user-facing interfaces, unlike some Android devices where IMSI retrieval codes work in certain configurations.
*#67# is sometimes listed as a way to reveal your call forwarding number for busy state. On current iOS, this may return a result but the behavior depends entirely on your carrier’s network implementation rather than iOS itself. Some users see results; others get error messages. Do not rely on it for security checks; use *#21# and *#62# instead, which have more consistent behavior across US carriers.
Codes claiming to reveal “hidden battery stats”, “secret performance modes”, or “factory settings” are misinformation. iOS does not expose these functions through dialer codes. Apple’s actual device diagnostic tools are accessible through the Battery Health section in Settings and through analytics data in Settings under Privacy, Analytics, and then Analytics Data, where daily device logs are stored. For actual battery health monitoring, Settings, Battery, Battery Health and Charging gives you the only officially exposed battery capacity metric. For context on how charging behavior affects that metric over time, the fast charging battery health guide covers what the capacity percentage actually means and when it becomes a meaningful concern.
Practical Summary: The Codes Worth Remembering
| Code | What It Does | When to Use It |
|---|---|---|
| *3001#12345#* + Call | Field Test Mode: real signal strength in dBm | Diagnosing weak signal, comparing coverage spots |
| *#06# | IMEI display, instant | Before selling, if stolen, for insurance claims |
| *#21# + Call | Call forwarding status check | Security check, especially after suspected SIM swap |
| ##002# + Call | Disable all call forwarding rules | If calls not delivering, or after suspected tampering |
| *#07# + Call | SAR (RF radiation) values | Regulatory research, device comparison |
| *#62# + Call | Voicemail forwarding number | Verify forwarding destination is carrier voicemail |
The ones worth memorizing or noting down: *#06# for IMEI (genuinely needed occasionally), *#21# for forwarding status (worth checking after any carrier account changes), and *3001#12345#* for field test if you are troubleshooting dead zones in your home or office. The rest are situational but useful to know exist.
For more iPhone features that are not obvious from the standard UI, the guide to scheduling text messages on iPhone covers another capability that most users do not know is natively available without a third-party app. And if you are looking at your iPhone camera quality and wondering about calibration, the iPhone 16 Pro Max camera overexposure fix covers adjustments that apply broadly to recent iPhone camera behavior.
Frequently Asked Questions
Are iPhone secret dialer codes safe to use?
Yes. The codes listed here are read-only diagnostic queries and carrier standard codes. None of them modify your device, erase data, or change settings (with the exception of ##002# which disables call forwarding, which is intentional and reversible). Field Test Mode in particular is read-only: it displays radio diagnostic data but cannot change any radio settings from the user interface. The codes have been in use for years and are documented by carriers and security researchers.
Do these codes work on all iPhone models?
*#06# and *#21# work on all iPhone models on all carriers as they use GSM standard commands. *3001#12345#* (Field Test Mode) works on all iPhones but the interface and data displayed changed significantly in iOS 14 and again in iOS 16. On iOS 17 and 18, the three-pane layout is current. Older iOS versions show a simpler single-screen view with fewer data points but still display rsrp0 signal strength values. Carrier-specific codes like *646# and *225# only work on their respective carriers.
What does the signal strength number in Field Test Mode mean?
The rsrp0 value in Field Test Mode represents your actual LTE or 5G signal strength. The scale runs from roughly -50 dBm (excellent signal) to -120 dBm (very poor signal). Values above -80 dBm give you reliable 4G LTE performance. Values between -80 and -100 dBm produce variable quality. Values below -100 dBm produce dropped calls and slow data. The bars on your status bar are a simplified and sometimes generous visual translation of this raw number.
Can these codes be used to hack or track an iPhone?
No. These are read-only query codes that retrieve information from your own device or your carrier’s network regarding your own line. They cannot access another person’s device, cannot intercept calls, and cannot modify any settings beyond the explicit forwarding commands (##002# disabling forwarding). If someone has physical access to your unlocked iPhone and enters forwarding commands, that is a physical security issue, not a dialer code vulnerability. The security concern runs in the other direction: using *#21# helps you detect if someone has already tampered with your forwarding settings.
