Hidden iPhone Service Codes You Should Know
Did you know that your iPhone has a set of secret service codes that reveal hidden diagnostic information and network details? These codes, often referred to as “iPhone service codes” or “secret menu codes,” are entered through the Phone app just like a regular phone number. They are primarily used by technicians and advanced users to test hardware features, troubleshoot issues, or monitor carrier signal strength.
Let’s explore some of the most useful service codes available on iPhones and what they can do.
What Are iPhone Service Codes?
Service codes are special number combinations—usually beginning with an asterisk (*) and ending with a pound sign (#)—that activate hidden menus or settings. On iPhones, these codes often provide information about the device’s performance, SIM card, or network connection.
While many Android phones support a wide array of service codes, iOS devices are more restricted. However, a few powerful codes still work and offer valuable insight.
Most Useful iPhone Service Codes
1. Field Test Mode – 3001#12345#
This is the most widely known and powerful iPhone service code. Dialing this code opens Field Test Mode—a hidden tool for advanced signal diagnostics. You’ll be able to see detailed information such as:
• Signal strength in decibels (RSSI)
• Cell tower ID and frequency band
• LTE, UMTS, and GSM metrics
To read signal strength in numerical form:
1. Open the Phone app.
2. Dial 3001#12345# and tap “Call.”
3. Look for the “RSRP” value under LTE for signal strength (e.g., -80 dBm is good, while -120 dBm is poor).
2. IMEI Code – #06#
This code instantly displays your iPhone’s IMEI (International Mobile Equipment Identity). It’s a unique identifier for your device and essential when unlocking, selling, or reporting it as lost.
3. Call Forwarding Info – #21#
This code lets you check if your calls, data, or messages are being forwarded. It’s helpful to verify if someone tampered with your call settings or if a forwarding service is active.
4. Call Waiting Status – #43#
Using this code, you can see whether call waiting is enabled on your line. This feature allows you to receive incoming calls even when you’re already on another call.
5. Call Barring Info – #33#
This code checks whether outgoing calls, messages, or data usage are restricted. It’s especially useful if you notice abnormal call behavior or blocked functions.
How to Use These Codes
1. Open the Phone app.
2. Dial the code exactly as written.
3. Press the Call button.
Some codes simply display information, while others allow you to toggle a setting (such as enabling or disabling call waiting).
Things to Keep in Mind
• Not all codes will work on every carrier or iOS version.
• Some menus are restricted or removed in newer iOS updates.
• These tools are designed for diagnostics, not customization—use them carefully.
• Unlike Android, iPhones don’t support codes to test specific hardware components (e.g., camera, battery, display).
Why Are These Codes Important?
Whether you’re troubleshooting network issues or checking if someone messed with your settings, service codes offer a powerful way to investigate your iPhone’s deeper systems. While the options are fewer compared to Android, they still provide hidden insights for tech-savvy users.
Knowing these iPhone service codes won’t replace professional support, but they can give you a head start when something feels off with your phone.
